Effects of transgenic <Emphasis Type="Italic">cry1Ie</Emphasis> maize on non-lepidopteran pest abundance,diversity and community composition

Non-lepidopteran pests are exposed to, and may be influenced by, Bt toxins when feeding on Bt maize that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt). In order to assess the potential effects of transgenic cry1Ie maize on non-lepidopteran pest species and ecological communities, a 2-year field study was conducted to compare the non-lepidopteran pest abundance, diversity and community composition between transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) by whole plant inspections. Results showed that Bt maize had no effects on non-lepidopteran pest abundance and diversity (Shannon–Wiener diversity index, Simpson’s diversity index, species richness, and Pielou’s index). There was a significant effect of year and sampling time on those indices analyzed. Redundancy analysis indicated maize type, sampling time and year totally explained 20.43 % of the variance in the non-lepidopteran pest community composition, but no association was presented between maize type (Bt maize and non-Bt maize) and the variance. Nonmetric multidimensional scaling analysis showed that sampling time and year, rather than maize type had close relationship with the non-lepidopteran pest community composition. These results corroborated the hypothesis that, at least in the short-term, the transgenic cry1Ie maize had negligible effects on the non-lepidopteran pest abundance, diversity and community composition.     

Distribution of denitrifying bacterial communities in the stratified water column and sediment–water interface in two freshwater lakes and the Baltic Sea

We have studied the distribution and community composition of denitrifying bacteria in the stratified water column and at the sediment–water interface in lakes Plußsee and Schöhsee, and a near-shore site in the Baltic Sea in Germany. Although environmental changes induced by the stratification of the water column in marine environments are known to affect specific populations of denitrifying bacteria, little information is available for stratified freshwater lakes and brackish water. The aim of the present study was to fill this gap and to demonstrate specific distribution patterns of denitrifying bacteria in specific aquatic habitats using two functional markers for the nitrite reductase (nirK and nirS genes) as a proxy for the communities. The leading question to be answered was whether communities containing the genes nirK and nirS have similar, identical, or different distribution patterns, and occupy the same or different ecological niches. The genes nirK and nirS were analyzed by PCR amplification with specific primers followed by terminal restriction fragment length polymorphism (T-RFLP) and by cloning and sequence analysis. Overall, nirS-denitrifiers were more diverse than nirK-denitrifiers. Denitrifying communities in sediments were clearly different from those in the water column in all aquatic systems, regardless of the gene analyzed. A differential distribution of denitrifying assemblages was observed for each particular site. In the Baltic Sea and Lake Plußsee, nirK-denitrifiers were more diverse throughout the water column, while nirS-denitrifiers were more diverse in the sediment. In Lake Schöhsee, nirS-denitrifiers showed high diversity across the whole water body. Habitat-specific clusters of nirS sequences were observed for the freshwater lakes, while nirK sequences from both freshwater lakes and the Baltic Sea were found in common phylogenetic clusters. These results demonstrated differences in the distribution of bacteria containing nirS and those containing nirK indicating that both types of denitrifiers apparently occupy different ecological niches.     

Effects of using different host plants and long-term fertilization systems on population sizes of infective arbuscular mycorrhizal fungi

The effect of cultivation of mycorrhizal and non-mycorrhizal plants and mineral fertilization on the arbuscular mycorrhizal fungal (AMF) community structure of maize (Zea mays L.) plants was studied. Soil samples were collected from two field experiments treated for 5 years with three fertilization systems (Control – no fertilization; Mineral – NPK fertilization; and Organic – Farmyard manure fertilization). Soil samples containing soil and root fragments of rapeseed (Brassica napus L., non-mycorrhizal plant) and wheat (Triticum aestivum L., mycorrhizal plant) collected from the field plots were used as native microbial inoculum sources to maize plants. Maize plants were sown in pots containing these inoculum sources for four months under glasshouse conditions. Colonization of wheat roots by AMF, AMF community structure, AMF diversity (Shannon’s index), AMF dominance (Simpson’s index) and growth of maize were investigated. Sixteen AMF species were identified from rhizosphere soil samples as different species of genera Acaulospora, Claroideoglomus, Dentiscutata, Funneliformis, Gigaspora, Quatunica, Racocetra, and Rhizoglomus. Maize plants grown in manure-fertilized soils had a distinct AMF community structure from plants either fertilized with mineral NPK-fertilizer or non-fertilized. The results also showed that inoculum from non-mycorrhizal plants combined with mineral fertilization decreased AMF diversity (Shannon’s index), AMF dominance (Simpson’s index) and growth of maize. Our findings suggest that non-mycorrhizal plants, such as B. napus, can negatively affect the presence and the effects of soil inoculation on maize growth. Also, our results highlight the importance of considering the long-term effect of rapeseed cultivation system on the reduction of population sizes of infective AMF, and its effect on succeeding annual crops.     

Antimicrobial endophytic fungal assemblages inhabiting bark of <Emphasis Type="Italic">Taxus baccata</Emphasis> L. of Indo-Burma mega biodiversity hotspot

Fungal endophytes were isolated from inner bark of Taxus baccata L., an important source of potent anticancer drug taxol. Bark samples were collected from two locations of Arunachal Pradesh, India, part of the Indo-Burma mega biodiversity hotspot, during two seasons i.e. monsoon and winter. Altogether 77 fungal strains representing 18 genera were isolated from T. baccata bark during the present investigation. The colonizing frequency was recorded as 38.5% and the fungal community comprised of 78% of Hyphomycetes, 5.2% of Coelomycetes, 2.6% of Zygomycetes and Ascomycetes and 9.1% of sterile mycelia. Most common and frequently isolated genera were Fusarium, Penicillium and Aspergillus. Simpson and Shannon diversity indices indicated higher species diversity during monsoon than during winter seasons irrespective of the locations. The two locations harbored 5 to 37 endophyte species and the similarity index was low during winter and high during monsoon. Ethyl acetate extract of fermentation cultures of these fungi were tested for their antimicrobial activity against a panel of human pathogenic Gram-positive and Gram-negative bacteria and fungi. Fifteen fungal isolates out of the isolated strains displayed antimicrobial activity. An endophytic fungus, identified as Fusarium sp. displayed significant antimicrobial activity against all the test pathogens.     

Response of performance and bacterial community to oligotrophic stress in biofilm systems for raw water pretreatment

Understanding the dynamics of performance and bacterial community of biofilm under oligotrophic stress is necessary for the process optimization and risk management in biofilm systems for raw water pretreatment. In this study, biofilm obtained from a pilot-scale biofilm reactor was inoculated into a pilot-scale experimental tank for the treatment of oligotrophic raw water. Results showed that the removal of NH₄ ⁺–N was impaired in biofilm systems when influent NH₄ ⁺–N was less than 0.35 mg L^?1 or NH₄ ⁺–N loading rate of less than 7.51 mg L^?1 day^?1. The dominant bacteria detected in biofilm of different carrier were obvious distinct from phylum to genus level under oligotrophic stress. The dominant bacteria in elastic stereo media carrier changed from Proteobacteria (51.1%) to Firmicutes (32.7%), while Proteobacteria was always dominant in suspended ball carrier after long-term operation under oligotrophic conditions. Oligotrophic stress largely decreased the functional bacteria for the removal of nitrogen and organics including many genera in Proteobacteria and Nitrospirae, but increased several genera with spore forming organisms or potential bacterial pathogens in ESM carrier mainly including Bacillus, Mycobacterium, Pseudomonas, etc.     

Lepidoptera Papilionoidea communities as a sentinel of biodiversity threat: the case of wild boar rooting in a Mediterranean habitat

Butterfly communities can be modified by the activities of large mammals. The wild boar (Sus scrofa) is one of the most common mammals in Europe and has notably expanded its distribution range in recent decades. The present work aimed to investigate the possible effect of wild boar rooting activity on butterflies in olive groves inside the “Cilento, Vallo di Diano and Alburni” National Park. Butterflies were surveyed in five Rooted (R) and five Control areas (C). Transects were made from April to September in 2011 and 2012. Forty-three species and 3659 individuals were found, of which 39 species and 2426 individuals were detected in C areas and 31 species and 1233 individuals in R areas. A community-level approach showed a significantly higher abundance, richness and Shannon–Wiener index in C than in R. An ecological-level approach indicated that more specialised butterflies were significantly more affected by wild boar activity. Finally, the response of single species was investigated: two species (Colias croceus and Polyommatus icarus) were significantly more represented in R, whereas six species (Aricia agestis, Hipparchia statilinus, Lasiommata megera, Melanargia arge, Pyronia cecilia and Thymelicus acteon) were significantly more abundant in C. Three species considered at risk (M. arge; Annex II of Directive 92/43/EEC; H. statilinus and T. acteon: European Red List) were less represented in rooted areas. Overall, the intensive wild boar activity negatively correlated with butterflies in the olive groves studied.     

A rare temperate terrestrial orchid selects similar Tulasnella taxa in ex situ and in situ environments

Mycorrhizal symbiosis in orchids is unique in that fungal presence is considered a requirement for germination as well as for further development. Additionally, orchid fungal associations can exhibit high specificity in nature. Yet, an important ecological question remains unanswered: ‘With which orchid mycorrhizal fungi (OMF) do un-inoculated orchid seedlings form symbiosis when cultured ex situ?’ Simultaneously, it is asserted that orchid conservation efforts involving ex situ plant culture should exclusively utilize natural symbionts of the respective orchid taxa. We present a first comparison of OMF communities within the roots of asymbiotically cultured plants of the rare orchid Platanthera chapmanii grown ex situ (ES), and those occurring naturally in situ (IS). Nuclear ribosomal internal transcribed spacer (nrITS) barcoding region was used to identify peloton forming OMF from roots collected between 2012 and 2014 from both growing environments. Our 114 sequences clustered into 11 operational taxonomic units (OTUs) belonging to four closely related clades of the fungal family Tulasnellaceae. Shannon–Wiener (H) and Simpson diversity (D) indices were similar (p = 0.81 for both) for ES and IS OMF communities. Beta diversity comparisons also showed similarity between ES and IS treatments based on weighted (p = 0.10) and unweighted (p = 0.20) Bray–Curtis dissimilarity matrices. Bayesian and Maximum Likelihood (ML) phylograms clustered ES and IS derived fungal OTUs into the same clades. Our data suggest that P. chapmanii: (1) forms symbiosis with taxonomically similar fungi in ex situ culture and in its native soil, and (2) exhibits a narrow phylogenetic breadth of mycorrhizal fungal OTUs within the Tulasnellaceae.     

Rapid start-up and performance of denitrifying granular sludge in an upflow sludge blanket (USB) reactor treating high concentration nitrite wastewater

Denitrifying granular sludge reactor holds better nitrogen removal efficiency than other kinds of denitrifying reactors, while this reactor commonly needs seeding anaerobic granular sludge and longer period for start-up in practice, which restricted the application of denitrifying granular sludge reactor. This study presented a rapid and stable start-up method for denitrifying granular sludge. An upflow sludge blanket (USB) reactor with packings was established with flocculent activated sludge for treatment of high concentration nitrite wastewater. Results showed mature denitrifying granular sludge appeared only after 15 days with highest nitrogen removal rate of 5.844 kg N/(m³ day), which was much higher than that of compared anoxic sequencing batch reactor (ASBR). No significant nitrite inhibition occurred in USB and denitrification performance was mainly influenced by hydraulic retention time, influent C/N ratio and internal reflux ratio. Hydraulic shear force created by upflow fluid, shearing of gaseous products and stable microorganisms adhesion on the packings might be the reasons for rapid achievement of granular sludge. Compared to inoculated sludge and ASBR, remarkable microbial communitiy variations were detected in USB. The dominance of Proteobacteria and Bacteroidetes and enrichment of species Pseudomonas_stutzeri should be responsible for the excellent denitrification performance, which further verified the feasibility of start-up method.     

Evaluation of microbial population dynamics in the co-composting of cow manure and rice straw using high throughput sequencing analysis

Microbial population dynamics in co-composting of cow manure and rice straw were evaluated using 16S high throughput sequencing technology. Physicochemical factors, including temperature, pH, nitrogen contents, the ratio of carbon and nitrogen, and germination index, were also determined in this study. 16S high throughput sequencing results showed that bacterial community structure and composition significantly varied in each phase of composting. The major phyla included Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria and Planctomycetes, respectively. Bacteroidetes and Proteobacteria were the most abundant phyla in all phases, and Actinobacteria was just dominant in the mesophilic phase, while Firmicutes and Planctomycetes were ubiquitous. At the genus level, Simiduia, Flavobacterium, unclassified Chitinophagaceae and Flexibacter notably changed in each phase of composting. Bacterial community diversity in the mesophilic phase was higher than that in others based on the Shannon–Wiener index and Simpson diversity index. The ratio of carbon and nitrogen and germination index indicated that the co-composting of cow manure and rice straw reached maturation. The result of nitrogen contents showed that nitrogen loss mainly occurred in the thermophilic phase. In addition, the differences in the distributions of key OTUs between in the late thermophilic phase and the cooling and maturation phase were unobvious compared with other phase’s base on the principal component analysis. Redundancy analysis revealed that the changes of nitrogen played a predominant role in the distributions of OTUs during the composting process.     

Phylogenetic Diversity of Microorganisms from the Sludge of a Biogas Reactor Processing Oil-Containing and Municipal Waste

High-throughput sequencing of the 16S rRNA gene fragments was used to determine the phylogenetic diversity of prokaryotes, including human pathogens, in the liquid phase of the sludge of a biogas reactor processing oil-containing and municipal waste. A unique microbial community was found to develop in the sludge, which comprised the microorganisms of municipal wastewater (bacteria of human feces) and specific groups of aerobic and anaerobic microorganisms, which possibly arrived with oil-containing water. In the 16S rRNA gene library, the sequences of representatives of Firmicutes prevailed (54.9%), which belonged to anaerobic bacteria of the genera Gelria (26.6%), Syntrophomonas (6.0%), Lutispora (2.0%), and uncultured Clostridia (group MBA03, 11.1%). The Proteobacteria sequences (20.7%) belonged mostly to the metabolically diverse members of the genus Pseudomonas (13.8%). The phylum Bacteroidetes (7%) was represented by uncultured bacteria (VadinBC27 wastewater-sludge group), while members of the phylum Cloacimonetes were mainly syntrophic bacteria Candidatus Cloacamonas (7.5%). The sequences of bacteria commonly occurring in oilfields (Clostridia, Anaerolinea, Bacteroidetes, sulfate-reducing Deltaproteobacteria, members of the family Syntrophaceae, and of the genera Thauera, Pseudomonas, Dechloromonas, and Petrimonas) were revealed. No sequences of bacteria known to be pathogenic to humans were found. The cultured microorganisms were aerobic organotrophic and anaerobic fermenting, denitrifying, and methanogenic prokaryotes. Fermenting and methanogenic enrichments grew on a broad range of organic substrates (sucrose, glycerol, starch), producing volatile fatty acids (acetate, n-butyrate, and propionate), gases (Н₂, СО₂, and CH₄), and decreasing pH of the medium from 7.0 to 4.5–5.0. The possible application of the biogas reactor sludge as a source of fermenting and methanogenic anaerobic prokaryotes, as well as of aerobic hydrocarbonoxidizing bacteria for oilfield introduction and for production of new preparations for enhanced oil recovery and for bioremediation of oil contamination is discussed.     

Diversity and Phenology of Wild Bees in a Highly Disturbed Tropical Dry Forest “Desierto de la Tatacoa”, Huila–Colombia

Colombian tropical dry forest is considered the most endangered tropical biome due to anthropic activities. Desierto de la Tatacoa (DsT) is an example of high disturbed tropical dry forest which still maintains a high biodiversity. The objective of the study was to record the diversity and phenology of wild bees in this place by monthly sampling between December 2014 and December 2016 in a 9-km² area. During the study, there was a prolonged El Niño–Southern Oscillation period. Bees were collected by entomological nets, malaise traps, eugenol scent trapping, and nest traps. Shannon index was calculated to estimate diversity and Simpson index to determine dominance of a species. The effect of environmental conditions (wet and dry season) in richness and abundance was analyzed by paired T tests. A total of 3004 bee specimens were collected, belonging to 80 species from Apidae, Megachilidae, Halictidae, and Colletidae. Apidae was the most diverse. Shannon index value was 2.973 (discarding Apis mellifera Linnaeus 1758 data); thus, DsT can be considered as a zone of high wild bee diversity. Dry and rainy season showed differences in diversity (p?<?0.05). Rainy season showed larger blooming periods and higher bee diversity than dry season. In both seasons, social species were dominant (e.g., A. mellifera or Trigona fulviventris Guérin 1844). Although DsT is a highly disturbed ecosystem, this study found it has the second highest number of genera and the fourth highest number of species reported in Colombia.     

Surface-attached and suspended bacterial community structure as affected by C/N ratios: relationship between bacteria and fish production

Bacteria play crucial roles in the combined system of substrate addition and C/N control, which has been demonstrated to improve aquaculture production. However, the complexity of surface-attached bacteria on substrates and suspended bacteria in the water column hamper further application of this system. This study firstly applied this combined system into the culture of grass carp, and then explored the relationship between microbial complexes from surface-attached and suspended bacteria in this system and the production of grass carp. In addition, this study investigated bacterial community structures as affected by four C/N ratios using Illumina sequencing technology. The results demonstrated that the weight gain rate and specific growth rate of grass carp in the CN20 group (C/N ratio 20:1) were the highest (P < 0.05), and dietary supplementation of the microbial complex had positive effects on the growth of grass carp (P < 0.05). Sequencing data revealed that, (1) the proportions of Verrucomicrobiae and Rhodobacter (surface-attached), sediminibacterium (suspended), and emticicia (surface-attached and suspended) were much higher in the CN20 group compared with those in the other groups (P < 0.05); (2) Rhodobacter, Flavobacterium, Acinetobacter, Pseudomonas, Planctomyces, and Cloacibacterium might be important for the microbial colonization on substrates; (3) as the C/N ratio increased, proportions of Hydrogenophaga (surface-attached and suspended), Zoogloea, and Flectobacillus (suspended) increased, but proportions of Bacillus, Clavibacter, and Cellvibro (surface-attached and suspended) decreased. In summary, a combined system of substrate addition and C/N control increased the production of grass carp, and Verrucomicrobiae and Rhodobacter in the surface-attached bacterial community were potential probiotic bacteria that contributed to the enhanced growth of grass carp.     

Comparison of the abundance and community structure of ammonia oxidizing prokaryotes in rice rhizosphere under three different irrigation cultivation modes

The abundance, diversity and community structure of ammonia oxidizing archaea (AOA) and bacteria (AOB) in rice rhizosphere soils under three different irrigation cultivated modes, named continuous irrigation mode (C), intermittent irrigation mode (I) and semi-arid mode (M), respectively, were investigated using amoA gene as a molecular biomarker. Clone libraries and quantitative polymerase chain reaction results indicated the highest number of archaeal amoA gene copy was detected in M cultivation mode, then in I and C, whereas, their order of amoA gene copy numbers were I > M > C for AOB, and those were obvious higher than in the bulk soil. The ratios of AOA/AOB were greater than 1 for all samples, suggested the predominance of AOA throughout the period of rice growth in the three different irrigation cultivation modes. Diversity index (S_Chao1 and Shannon H) have an obvious variation in three different irrigation cultivation modes. For AOA, S_Chao1 was highest in M and lowest in I mode, whereas, Shannon H was highest in M cultivation mode and lowest in C mode. For AOB, mode M exhibited the highest diversity index (S_Chao1 and Shannon H), while C showed the lowest highest diversity, suggested long-term water input (continuous mode) may decrease diversity of ammonia oxidizers, whereas mode M may be more appropriate for them. In addition, AOA sequences fall within Nitrososphaera, Nitrosopumilus and Nitrosotalea cluster with proportion of 89.38, 8.85 and 1.77 %, respectively. AOB gene sequences belonged to the Nitrosomonas and Nitrosospira genera with proportion of 90.97 and 9.03 %, respectively. In addition, the abundances, diversity and community structure had an obvious temporal variation in three developmental stages of rice, further suggested rice growth obviously affected the ammonia oxidizing prokaryotes in their rhizosphere soil.     

Biofilm-associated indole acetic acid producing bacteria and their impact in the proliferation of biofilm mats in solar salterns

Biofilm mats appear in salterns distinctively during the monsoon season when the salinity decreases below 12 percentile salinity units and within a short period cover the entire surface area of the saltern. A study was carried out in two salterns viz. Nerul and Curca to find a possible reason for the rapid proliferation of these solar biofilms. Out of the 125 bacteria isolated from these biofilms, 16 produced indole-3-acetic acid (IAA). Rapid in-situ assay with Salkowski reagent and HPLC analysis confirmed the IAA production. Four isolates consistently produced high IAA concentrations ranging from 9.5 to 14.2 μg/mL in the presence of 4 mg/mL tryptophan concentrations in the growth media. The IAA-producing bacteria were Aeromonas aquariorum (N2), Pseudomonas alcaliphila (N3), Vibrio diazotrophicus (N6) and Pseudomonas pachastrellae (C3). These four IAA-producing bacteria also produced other growth promoting factors like ammonia. Three isolates produced siderophores and were phosphate solubilizers. There was enhancement in the growth of Cicer arietinum (length of the shoot and root) under axenic conditions and of biofilm mats (r = 0.9, p < 0.001; r = 0.8, p < 0.05 and r = 0.946, p < 0.01, respectively). This is, according to our knowledge, the first report indicating IAA-producing bacteria isolated from biofilms enhancing the proliferation of these biofilm mats in the solar salterns.     

Effect of long-term different fertilization on bacterial community structures and diversity in citrus orchard soil of volcanic ash

This study was conducted to assess bacterial species richness, diversity and community distribution according to different fertilization regimes for 16 years in citrus orchard soil of volcanic ash. Soil samples were collected and analyzed from Compost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost (14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000 kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a), and Control (no fertilization) plot which have been managed in the same manners with compost and different amount of chemical fertilization. The range of pyrosequencing reads and OTUs were 4,687–7,330 and 1,790–3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannon index were higher in 1/2 NPK+compost than other treatments, which were 15,202, 9,112, 7.7, respectively. Dominant bacterial groups at level of phylum were Proteobacteria, Acidobacteria, and Actinobacteria. Those were occupied at 70.9% in 1/2 NPK+compost. Dominant bacterial groups at level of genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteria in Compost. Soil pH displayed significantly closely related to bacterial species richness estimates such as Ace, Chao1 (p<0.05) and Shannon index (p<0.01). However, it showed the negative correlation with exchangeable aluminum contents (p<0.05). In conclusion, diversity of bacterial community in citrus orchard soil was affected by fertilization management, soil pH changes and characteristics of volcanic ash.     

Bio-optical characterization of selected cyanobacteria strains present in marine and freshwater ecosystems

The optical properties, i.e., absorption and scattering spectra of ten strains of cyanobacteria from the Baltic Sea and Pomeranian lakes (Aphanizomenon flos-aquae KAC 15, Microcystis aeruginosa CCNP 1101, Anabaena sp. CCNP 1406, Synechocystis salina CCNP 1104, Phormidium sp. CCNP 1317, Nodularia spumigena CCNP 1401, Synechococcus sp. CCNP 1108, Nostoc sp. CCNP 1411, Cyanobacterium sp. CCNP 1105, Pseudanabaena cf. galeata CCNP 1312) grown under low light conditions were investigated. Moreover, the chlorophylls, carotenoids, and phycobilin composition as well as the size structure of chosen cyanobacteria were measured. Studied species revealed high diversity both in optical properties with the absorption spectra similarity index ranging from 0.67 to 0.94 and the pigment composition. The chlorophyll-specific absorption coefficient at 440 nm a _ph *(440) varied between 0.017 and 0.065 m² mg^?1. The influence of the package effect was only observed in the case of large filamentous cyanobacteria like N. spumigena or Nostoc sp. Interestingly, the package effect factor Q _a *(675) for large-celled Anabaena sp. was 0.92. Besides chlorophyll a, only echinenone, β-carotene, and phycocyanin were present in all analyzed cyanobacteria strains. Zeaxanthin, which is widely used as a marker pigment for cyanobacteria, was absent in the toxic N. spumigena and Anabaena sp., which are the species that occur in the Baltic Sea most frequently causing summer cyanobacterial blooms. The investigation also showed that the sample preservation technique can introduce some major errors within the absorption band affected by the phycocyanin absorption.     

Ichthyofaunal Assemblage of the Dianshan Lake,Shanghai, China: Implications for Management

Ichthyofaunal diversity of the Dianshan lake in Shanghai, China was assessed during the year 2013 from samples of finfish harvested using fleets of gillnets and trawls of different mesh sizes with the aim of generating necessary data that could support sustainable use of finfish in this lake. Morphometric parameters of specimens caught were taken following standard procedures. Totally 21,308 specimens belonging to 40 species, 15 families and 7 orders were encountered throughout the study period. Seasonal abundance was lowest (395 individuals) during March (spring) and highest (4428 individuals) during August (summer). Cyprinidae was the dominant family (22 species) and Coilia ecetenes taihuensis was the most abundant species (30.69%), followed by Acheilognathus taenianalis (17.8618%), Plagiognathops microlepis (16.567%), Carassius auratus (14.492%). The evenness, richness and biodiversity of the faunal assemblage were also evaluated by Shannon–Wiener index (H′), Margalef’s diversity Index (d) and evenness index (J) respectively. Hypophthalmichthys nobilis was the largest and heaviest fish (34.909 cm, FL; 889.355 g, W), the smallest fish in length recorded was Odontamblyopus rubicundus (4.19 cm) while Plecoglossus altivelis altivelis (1.1 g) was the lowest in terms of mean weight. The mean condition factor for all fish species was (K = 1.72), showing fish species were generally in ‘good’ condition. Fluctuations in species occurrence and abundance noted in our study may be accounted from the variation in the physico-chemical parameters of the Lake in respect to time. But, under such a situation it is evident that the small fish species increased to a great extent and a few like Coilia ecetenes taihuensis became the dominant.     

General medium for the autotrophic cultivation of acetogens

Syngas fermentation, a microbial process in which synthesis gas serves as a substrate for acetogens, has attracted increasing interest in the last few years. For the purposeful selection of acetogens for various applications, it would be useful to characterize and compare the process performances of as many autotrophic strains as possible under identical process conditions. Unfortunately, all the media compositions so far recommended for syngas fermentation differ considerably with respect to each individual strain. Therefore, a general medium for syngas fermentation was designed. The suitability of this new general-acetogen medium (GA-medium) was proven based on the autotrophic batch cultivation of Acetobacterium fimetarium, Acetobacterium wieringae, Blautia hydrogenotrophica, Clostridium magnum, Eubacterium aggregans, Sporomusa acidovorans, Sporomusa ovata and Terrisporobacter mayombei in anaerobic flasks with an initial gas phase of H₂:CO₂ (66:34) (P = 200 kPa). A comparison of the autotrophic batch processes with this medium revealed T. mayombei as the bacterium with the highest maximum growth rate of 5.77 day^?1 which was more than 10 times higher than the lowest identified maximum growth rate of A. fimetarium. The maximum growth rates of A. wieringae, C. magnum and S. acidovorans were all in the same order of magnitude around 1.7 day^?1. The newly designed GA-medium offers the possibility to compare autotrophic process performances of different acetogens under similar conditions absent the effects of various media compositions.     

Perchlorate reduction by hydrogen autotrophic bacteria and microbial community analysis using high-throughput sequencing

Hydrogen autotrophic reduction of perchlorate have advantages of high removal efficiency and harmless to drinking water. But so far the reported information about the microbial community structure was comparatively limited, changes in the biodiversity and the dominant bacteria during acclimation process required detailed study. In this study, perchlorate-reducing hydrogen autotrophic bacteria were acclimated by hydrogen aeration from activated sludge. For the first time, high-throughput sequencing was applied to analyze changes in biodiversity and the dominant bacteria during acclimation process. The Michaelis–Menten model described the perchlorate reduction kinetics well. Model parameters q _max and K _s were 2.521–3.245 (mg ClO₄ ^?/gVSS h) and 5.44–8.23 (mg/l), respectively. Microbial perchlorate reduction occurred across at pH range 5.0–11.0; removal was highest at pH 9.0. The enriched mixed bacteria could use perchlorate, nitrate and sulfate as electron accepter, and the sequence of preference was: NO₃ ^? > ClO₄ ^? > SO₄ ^2?. Compared to the feed culture, biodiversity decreased greatly during acclimation process, the microbial community structure gradually stabilized after 9 acclimation cycles. The Thauera genus related to Rhodocyclales was the dominated perchlorate reducing bacteria (PRB) in the mixed culture.     

Above-ground arthropod community structure and influence of structural-retention management in southern Patagonian scrublands,Argentina

Southern Patagonia’s landscape hosts several semi-natural habitats, traditionally used for sheep production, such as Mulguraea tridens and Lepidophyllum cupressiforme scrublands. Mulguraea scrublands are managed via mechanical shredding to remove shrubs and increase grass availability, alternating with structural-retention strips. We analyzed the influence of structural-retention management (with cut and retention strips) in Mulguraea scrublands with regards to above-ground arthropod community structure, as well as differences between the two natural scrubland types. We worked in Santa Cruz Province (Argentina) with pitfall traps during two summers in the first 2 years after mechanical shredding. Richness, abundance, occurrence frequency, Shannon–Wiener diversity and Pielou evenness indices, and similarity among assemblages were evaluated using univariate and multivariate statistical tests. Complementarily, we described vegetation ground cover and microclimate. We collected 3279 individuals from 38 species belonging to Insecta and Arachnida Classes. Shannon–Wiener diversity and Pielou evenness indices, as well as the overall assemblages, differed significantly between managed cut strips and natural Mulguraea scrublands, mainly due to the loss and introduction of species from surrounding environments; abundance also differed in the first sampling year compared to the second year. Likewise, managed retention strips allowed the partial maintenance of arthropod community structure and had a microclimate that was similar to natural Mulguraea scrublands, although assemblages in managed cut and retention strips became more similar among themselves in the second sampling year. On the other hand, richness, abundance and assemblage of both natural scrubland types differed significantly, with 87?% more indicator species in Mulguraea than in Lepidophyllum scrublands. Greater dissimilarity occurred between both natural scrubland types in dryer years, which could be related with an El Niño Southern Oscillation event. If arthropod community structure changes prove stable over time, mechanical shredding with structural-retention management would allow for an increase in the sheep carrying capacity, while reducing impacts to the arthropod community, thus providing a viable compromise between productivity and conservation in a fragile arid environment. More studies are necessary to evaluate long term changes in above-ground arthropod community structure of scrublands in arid zones of southern Patagonia.