Comparison of bioethanol production from cultivated versus wild <Emphasis Type="Italic">Gracilaria verrucosa</Emphasis> and <Emphasis Type="Italic">Gracilaria gigas</Emphasis>

The seaweed genus Gracilaria is a potential candidate for the production of bioethanol due to its high carbohydrate content. Gracilaria is abundant throughout the world and can be found in both wild and cultivated forms. Differences in the ecological factors such as temperature, salinity, and light intensity affecting wild and cultivated specimens may influence the biochemical content of seaweeds, including the carbohydrate content. This study aimed to investigate the proximate composition and potential bioethanol production of wild and cultivated G. gigas and G. verrucosa. Bioethanol was produced using separate hydrolysis fermentation (SHF), employing a combination of enzymatic and acid hydrolysis, followed by fermentation with Saccharomyces cerevisiae ATCC 200062. The highest carbohydrate content was found in wild G. gigas. The highest galactose and glucose contents (20.21 ± 0.32 and 9.70 ± 0.49 g L^?1, respectively), as well as the highest production of bioethanol (3.56 ± 0.02 g L^?1), were also found in wild G. gigas. Thus, we conclude that wild G. gigas is the most promising candidate for bioethanol production. Further research is needed to optimize bioethanol production from wild G. gigas. Domestication of wild G. gigas is a promising challenge for aquaculture to avoid overexploitation of this wild seaweed resource.     

Hemato-Immunological Responses and Disease Resistance in Siberian Sturgeon <Emphasis Type="Italic">Acipenser baerii</Emphasis> Fed on a Supplemented Diet of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis>

A feeding trial was conducted to investigate the effects of different levels of dietary Lactobacillus plantarum on hemato-immunological parameters and resistance against Streptococcus iniae infection in juvenile Siberian sturgeon Acipenser baerii. Fish (14.6 ± 2.3 g) were fed three experimental diets prepared by supplementing a basal diet with L. plantarum at different concentrations [1 × 10⁷, 1 × 10⁸ and 1 × 10⁹ colony-forming units (cfu) g^?1] and a control (non-supplemented basal) diet for 8 weeks. Innate immune responses (immunoglobulin (Ig), alternative complement activity (ACH50) and lysozyme activity) were significantly higher in fish fed the 1 × 10⁸ and 1 × 10⁹ cfu g^?1 L. plantarum diet compared to the other groups (P < 0.05). Furthermore, fish fed on various levels of L. plantarum significantly showed higher red blood cell (RBC), hemoglobin (Hb), white blood cell (WBC) and monocyte compared to those of the control group (P < 0.05). At the end of the feeding experiment, some fish were challenged with S. iniae to quantify the level of disease resistance. The mortality after S. iniae challenge was decreased in fish fed a probiotic. These results indicated that dietary supplementation of L. plantarum improved immune response and disease resistance of Siberian sturgeon juvenile.     

Association between <Emphasis Type="Italic">cagA</Emphasis>, <Emphasis Type="Italic">vacAi</Emphasis>, and <Emphasis Type="Italic">dupA</Emphasis> genes of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> and gastroduodenal pathologies in Chilean patients

In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups—non-severe and severe gastric pathologies—and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p < 0.0001; OR = 8.75; 95% CI 3.54–21.64). Conversely, cagA (p = 0.3507; OR = 1.62; 95% CI 0.59–4.45) and vacAi2 (p = 0.0114; OR = 3.09; 95% CI 1.26–7.60) genes were not associated with damage, while the dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09–0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.     

<Emphasis Type="Italic">Talaromyces heiheensis</Emphasis> and <Emphasis Type="Italic">T. mangshanicus</Emphasis>, two new species from China

Two new species, Talaromyces heiheensis from rotten wood and T. mangshanicus isolated from soil, are illustrated and described as new to science in sections Trachyspermi and Talaromyces. The phylogenetic positions of the two new species inferred from the internal transcribed spacer, beta-tubulin, calmodulin and RNA polymerase II second largest subunit regions were carried out. Talaromyces heiheensis is phylogenetically closely related to T. albobiverticillius, T. rubrifaciens, T. solicola and T. erythromellis, and characterised by slow growth on Czapek yeast autolysate agar at 25 °C, orange conidia en masse on malt extract agar at 25 °C, biverticillate and terverticillate conidiophores, acerose phialides and subglobose to ellipsoidal, smooth-walled conidia. Talaromyces mangshanicus is related to T. kendrickii, T. qii and T. thailandensis, and characterised by slow-growing colonies with absent or sparse sporulation on CYA agar at 25 °C, conidia en masse greyish purple, purplish red soluble pigment on yeast extract agar (YES) at 25 °C, biverticillate conidiophores, ampulliform phialides and subglobose to ellipsoidal conidia with echinulate walls. They are distinguished from the known species in culture characteristics on four standard media, microscopic features and sequence data.     

The fitness of the cotton mealybug <Emphasis Type="Italic">Phenacoccus solenopsis</Emphasis> (Tinsley) is reduced after feeding on virus-infected <Emphasis Type="Italic">Hibiscus rosa</Emphasis>-<Emphasis Type="Italic">sinensis</Emphasis>

The cotton mealybug Phenacoccus solenopsis (Tinsley) and Cotton leaf curl Multan virus (CLCuMV), serious threats to economic crops and garden plants, have invaded southern China and widely infected Hibiscus rosa-sinensis. Whether an inter-species connection has facilitated the invasion process is unclear. In this study the interaction between P. solenopsis and H. rosa-sinensis infected with CLCuMV was investigated in the laboratory. We observed that 1st and 2nd instar nymphs of P. solenopsis preferred to feed on healthy H. rosa-sinensis leaves, whereas 3rd instar nymphs and female adults had no preference between healthy and virus-infected H. rosa-sinensis leaves. The developmental time of each P. solenopsis developmental stage increased significantly after feeding on infected H. rosa-sinensis leaves (p < 0.05). In particular, the development time for 2nd instar female and male nymphs and 3rd instar female nymphs increased by approximately twofold. The generation time of female mealybugs increased from 25.84 d on healthy H. rosa-sinensis to 32.12 d when feeding on CLCuMV-infected H. rosa-sinensis, and the survival rate decreased from 71.04 % on healthy H. rosa-sinensis to 5.80 % on infected plants. Nymph survival was most affected by feeding on infected plants. Additionally, the fecundity of female mealybugs feeding on infected H. rosa-sinensis decreased by 47.8 %. Thus, feeding on CLCuMV-infected H. rosa-sinensis significantly decreased the biological fitness and invading and colonizing abilities of P. solenopsis.     

Molecular evidence for hybridization between invasive <Emphasis Type="Italic">Solidago canadensis</Emphasis> and native <Emphasis Type="Italic">S</Emphasis>. <Emphasis Type="Italic">virgaurea</Emphasis>

Hybridization between alien and native species is biologically very important and could lead to genetic erosion of native taxa. Solidago × niederederi was discovered over a century ago in Austria and described by Khek as a natural hybrid between the alien (nowadays regarded also as invasive) S. canadensis and native S. virgaurea. Although interspecific hybridization in the genus Solidago is considered to be relatively common, hybrid nature of S. × niederederi has not been independently proven using molecular tools, to date. Because proper identification of the parentage for the hybrid Solidago individuals solely based on morphological features can be misleading, in this paper we report an additive polymorphism pattern expressed in the ITS sequences obtained from individuals representing S. × niederederi, and confirm the previous hypothesis that the parental species of this hybrid are S. canadensis and S. virgaurea. Additionally, based on variability at the cpDNA rpl32-trnL locus, we showed that in natural populations hybridization occurs in both directions.     

Distribution and habitats of <Emphasis Type="Italic">Phengaris</Emphasis> (<Emphasis Type="Italic">Maculinea</Emphasis>) butterflies and population ecology of <Emphasis Type="Italic">Phengaris</Emphasis><Emphasis Type="Italic">teleius</Emphasis> in China

Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.     

Acaricidal active fractions from acetone extract of <Emphasis Type="Italic">Aloe vera</Emphasis> L. against <Emphasis Type="Italic">Tetranychus cinnabarinus</Emphasis> and <Emphasis Type="Italic">Panonychus citri</Emphasis>

This study aimed to isolate acaricidal active fractions from acetone extract of Aloe vera L. and investigate the toxicity of these fractions against Tetranychus cinnabarinus (T. cinnabarinus) and Panonychus citri (P. citri). Acetone extract of A. vera L. was isolated by immersing in acetone for 72 h, and diverse fractions were fractionated by column chromatography. The acaricidal activity of each fractions was evaluated by corrected mortality of T. cinnabarinus through slide-dip bioassay. The 8th and 13th fractions of acetone extract with good acaricidal activity were indentified by LC/MS, and the toxicity of these two fractions to T. cinnabarinus and P. citri was identified by regression analysis. Acetone extract of A. vera L. exhibited obvious acaricidal activity, from which a total of 18 fractions were isolated. The 8th and 13th fractions with strong acaricidal activity against T. cinnabarinus were identified to be 3-O-alpha-d-mannopyranosyl-d-mannopyranose (OAMM) and aloe emodin. When compared with spirodiclofen, both OAMM and aloe emodin exhibited higher toxicity to T. cinnabarinus, while only OAMM exhibited a higher toxicity to P. citri (P < 0.05). OAMM and aloe emodin isolated from acetone extract of A. vera L. exhibited obvious acaricidal activities against T. cinnabarinus and P. citri.     

Artificial reefs for sea cucumber aquaculture confirmed as settlement substrates of the moon jellyfish <Emphasis Type="Italic">Aurelia coerulea</Emphasis>

In coastal areas with a high intensity of human activities, expansion of artificial structures may enhance Aurelia spp. blooms because these constructions may provide additional substrates for the settlement and proliferation of the polyps. In the present study, the possible occurrence and distribution of Aurelia coerulea ephyrae and polyps were investigated in sea cucumber (Apostichopus japonicus) culture ponds that contain huge amounts of artificial structures. Our results showed that A. coerulea ephyrae were widely distributed in the A. japonicus culture ponds along the Bohai and Yellow Seas. Furthermore, underwater photography revealed that polyps of A. coerulea mainly occurred on the undersides of the artificial reefs made by plastic sunshade nets, tiles and substrate cages. The artificial reefs may decrease the time A. coerulea planulae spend settling, provide more hidden, calm and shady places for the settlement and proliferation of A. coerulea planulae, and thus were suitable substrates for the moon jellyfish A. coerulea. Our study suggests that the A. japonicus culture ponds may act as nursery grounds for the jellyfish A. coerulea and may potentially enhance the blooms of this species in the coastal waters along the Bohai and Yellow Seas.     

The <Emphasis Type="Italic">yajC</Emphasis> gene from <Emphasis Type="Italic">Lactobacillus buchneri</Emphasis> and <Emphasis Type="Italic">Escherichia coli</Emphasis> and its role in ethanol tolerance

The yajC gene (Lbuc_0921) from Lactobacillus buchneri NRRL B-30929 was identified from previous proteomics analyses in response to ethanol treatment. The YajC protein expression was increased by 15-fold in response to 10 % ethanol vs 0 % ethanol. The yajC gene encodes the smaller subunit of the preprotein translocase complex, which interacts with membrane protein SecD and SecF to coordinate protein transport and secretion across cytoplasmic membrane in Escherichia coli. The YajC protein was linked to sensitivity to growth temperatures in E. coli, involved in translocation of virulence factors during Listeria infection, and stimulating a T cell-mediated response of Brucella abortus. In this study, the L. buchneri yajC gene was over-expressed in E. coli. The strain carrying pET28byajC that produces YajC after isopropyl β-d-1-thiogalactopyranoside induction showed tolerance to 4 % ethanol in growth media, compared to the control carrying pET28b. This is the first report linking YajC to ethanol stress and tolerance.     

Contrasting the early life histories of sympatric Arctic gadids <Emphasis Type="Italic">Boreogadus saida</Emphasis> and <Emphasis Type="Italic">Arctogadus glacialis</Emphasis> in the Canadian Beaufort Sea

The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener’s index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species.     

Effects of macrophyte leachate on <Emphasis Type="Italic">Anabaena</Emphasis> sp. and <Emphasis Type="Italic">Chlamydomonas moewusii</Emphasis> growth in freshwater tropical ecosystems

This study reports on the effects of dissolved organic matter (DOM) derived from the aquatic macrophyte Pistia stratiotes (collected from a tropical reservoir) on the mixotrophic growth of two phytoplankton species (Chlamydomonas moewusii and Anabaena sp.). The DOM from P. stratiotes had a mainly aliphatic structure, low molecular weight, low cellulose and lignin content and high carbon content. The addition of DOM (5% v/v) significantly decreased the growth rate of Anabaena sp. but increased the chlorophyll a concentration of C. moewusii. Higher light intensity (100 versus 30 µmol m^?2 s^?1) was important for Anabaena sp., increasing its growth rate and chlorophyll content. The use of DOM from P. stratiotes to mitigate cyanobacterial blooms should be further explored in future studies.     

Molecular characterization and expression analysis of <Emphasis Type="Italic">Hsp90</Emphasis> in <Emphasis Type="Italic">Schizothorax prenanti</Emphasis>

Aquatic animals suffer from various environmental stresses because the aquatic environment is a very complex system. To monitor the health status of fish, Hsp90 a potential early warning marker was determined in Schizothorax prenanti after infection with a bacterium. In this study, we cloned Hsp90 from S. prenanti for the first time. The full-length cDNA sequence of SpHsp90 was 2663 bp, contains an open reading frame of 2181 bp, and has a gene encoding 726 amino acids, an estimated molecular mass of 83.38 kDa, and a theoretical isoelectric point of 4.91. The SpHsp90 amino acid sequence has five conserved HSP90 family signatures and shares 87.0–95.5 % identity with other vertebrates. Phylogenetic analysis and structure comparison indicated that SpHsp90 should be a β isoform of the HSP90 family. SpHsp90 was ubiquitously expressed in all examined tissues, and the highest level of expression was in the kidney. After Streptococcus agalactiae infection, the level of SpHsp90 expression had significant changes (P < 0.05) in the hepatopancreas, spleen, kidney, and blood. The expression increased to the highest level at 6 h in the blood and at 24 h in the hepatopancreas, spleen, and kidney. The results suggested that the SpHsp90 gene could be induced by S. agalactiae in S. prenanti and that SpHsp90 may be involved in resistance to bacterial infection and provide an early warning information. The kidney is the most suitable for detecting SpHsp90 after bacterial infection.     

<Emphasis Type="Italic">R</Emphasis>-acetoin accumulation and dissimilation in <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis>

Klebsiella pneumoniae is a 2,3-butanediol producer, and R-acetoin is an intermediate of 2,3-butanediol production. R-acetoin accumulation and dissimilation in K. pneumoniae was studied here. A budC mutant, which has lost 2,3-butanediol dehydrogenase activity, accumulated high levels of R-acetoin in culture broth. However, after glucose was exhausted, the accumulated R-acetoin could be reused by the cells as a carbon source. Acetoin dehydrogenase enzyme system, encoded by acoABCD, was responsible for R-acetoin dissimilation. acoABCD mutants lost the ability to grow on acetoin as the sole carbon source, and the acetoin accumulated could not be dissimilated. However, in the presence of another carbon source, the acetoin accumulated in broth of acoABCD mutants was converted to 2,3-butanediol. Parameters of R-acetoin production by budC mutants were optimized in batch culture. Aerobic culture and mildly acidic conditions (pH 6–6.5) favored R-acetoin accumulation. At the optimized conditions, in fed-batch fermentation, 62.3 g/L R-acetoin was produced by budC and acoABCD double mutant in 57 h culture, with an optical purity of 98.0 %, and a substrate conversion ratio of 28.7 %.     

Engineering of <Emphasis Type="Italic">Escherichia coli</Emphasis> for the synthesis of <Emphasis Type="Italic">N</Emphasis>-hydroxycinnamoyl tryptamine and serotonin

Plants synthesize various phenol amides. Among them, hydroxycinnamoyl (HC) tryptamines and serotonins exhibit antioxidant, anti-inflammatory, and anti-atherogenic activities. We synthesized HC–tryptamines and HC–serotonin from several HCs and either tryptamine or serotonin using Escherichia coli harboring the 4CL (4-coumaroyl CoA ligase) and CaHCTT [hydroxycinnamoyl-coenzyme A:serotonin N-(hydroxycinnamoyl)transferase] genes. E. coli was engineered to synthesize N-cinnamoyl tryptamine from glucose. TDC (tryptophan decarboxylase) and PAL (phenylalanine ammonia lyase) along with 4CL and CaHCTT were introduced into E. coli and the phenylalanine biosynthetic pathway of E. coli was engineered. Using this strategy, approximately 110.6 mg/L of N-cinnamoyl tryptamine was synthesized. By feeding 100 μM serotonin into the E. coli culture, which could induce the synthesis of cinnamic acid or p-coumaric acid, more than 99 μM of N-cinnamoyl serotonin and N-(p-coumaroyl) serotonin were synthesized.     

Complete chloroplast genome sequence of <Emphasis Type="Italic">Capsicum</Emphasis><Emphasis Type="Italic">baccatum</Emphasis> var. <Emphasis Type="Italic">baccatum</Emphasis>

Molecular markers derived from the complete chloroplast genome can provide effective tools for species identification and phylogenetic resolution. Complete chloroplast (cp) genome sequences of Capsicum species have been reported. We herein report the complete chloroplast genome sequence of Capsicum baccatum var. baccatum, a wild Capsicum species. The total length of the chloroplast genome is 157,145 bp with 37.7 % overall GC content. One pair of inverted repeats, 25,910 bp in length, was separated by a small single-copy region (17,974 bp) and large single-copy region (87,351 bp). This region contains 86 protein-coding genes, 30 tRNA genes, 4 rRNA genes, and 11 genes contain one or two introns. Pair-wise alignments of chloroplast genome were performed for genome-wide comparison. Analysis revealed a total of 134 simple sequence repeat (SSR) motifs and 282 insertions or deletions variants in the C. baccatum var. baccatum cp genome. The types and abundances of repeat units in Capsicum species were relatively conserved, and these loci could be used in future studies to investigate and conserve the genetic diversity of the Capsicum species.     

Molecular cytogenetic characterization of <Emphasis Type="Italic">Triticum timopheevii</Emphasis> chromosomes provides new insight on genome evolution of <Emphasis Type="Italic">T. zhukovskyi</Emphasis>

Triticum timopheevii (2n = 4x = 28, GGA^tA^t) is a tetraploid wheat formerly cultivated in western Georgia. The natural allopolyploid Triticum zhukovskyi is a hexaploid taxon originated from hybridization of T. timopheevii with cultivated einkorn T. monococcum (2n = 2x = 14, A^mA^m). Karyotypically T. timopheevii and T. zhukovskyi differ from other tetraploid and hexaploid wheats and were assigned to the section Timopheevii of the genus Triticum L. Triticum timopheevii and T. zhukovskyi are resistant to many fungal diseases and therefore could potentially be utilized for wheat improvement. We were aiming to precisely identify all T. timopheevii chromosomes and to trace the evolution of T. zhukovskyi. For this, we developed a set of molecular cytogenetic landmarks based on eleven DNA probes. Each chromosome can now be characterized by two to eight probes. The pTa-535 sequence allows the identification of all A^t-genome chromosomes, whereas G-genome and some A^t-genome chromosomes can be identified using (GAA/CTT) _n and pSc119.2 probes. The probes pAesp_SAT86, pAs1, Spelt-1, Spelt-52 and 5S and 45S rDNA can be applied as additional markers to discriminate particular chromosomes or chromosomal regions. The distribution of (GAA/CTT) _n , pTa-535 and pSc119.2 DNA probes on T. timopheevii chromosomes is distinct from other tetraploid wheats and can therefore be used to track individual chromosomes in introgression programs. Our study confirms the origin of T. zhukovskyi from hybridization of T. timopheevii with T. monococcum; however, we show that the emergence was accompanied by changes involving mostly A^t-genome chromosomes. This may be due to the presence of two closely related A-genomes in the T. zhukovskyi karyotype.     

Properties of Probiotics <Emphasis Type="Italic">Kocuria</Emphasis> SM1 and <Emphasis Type="Italic">Rhodococcus</Emphasis> SM2 Isolated from Fish Guts

This study characterized probiotics Kocuria SM1 and Rhodococcus SM2, which were recovered from the intestinal microbiota of rainbow trout (Oncorhynchus mykiss, Walbaum). The cultures were Gram-positive, non-motile, catalase-positive and oxidase-negative cocci or rods. Cell multiplication of SM1 and SM2 was observed at 4–37 °C (45 °C for SM1), in 0–20% (w/v) NaCl and at pH 2–11. The viability was not affected when exposed to pepsin at pH 2.0 and 3.0, and pancreatin at pH 8.0. Neither isolates were chrome azurol S-positive for siderophore production. Of the 19 common enzymes analysed using the API-ZYM system, only 8 were evident in the culture of SM1 compared to 11 enzymes for SM2. The secondary metabolites of both probiotics were inhibitory to Acinetobacter baumannii, Vibrio anguillarum and V. ordalii; SM2 inhibited Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. SM2 was resistant to penicillin and sulphatriad, out of six antimicrobial agents; SM1 was resistant to sulphatriad. These results suggest that Kocuria SM1 and Rhodococcus SM2 are able to grow over a wide range of temperature, salinity and pH, including in conditions that mimic the gastrointestinal environment of fish and produce extracellular enzymes that may have a role in the host digestive processes. Importantly, Rhodococcus SM2 displays a high degree of bacteriocinogenic potential against multi-drug-resistant human pathogens that have never been documented among the gut microbiota of fish.     

<Emphasis Type="Italic">Sphingorhabdus buctiana</Emphasis> sp. nov., isolated from fresh water,and reclassification of <Emphasis Type="Italic">Sphingopyxis contaminans</Emphasis> as <Emphasis Type="Italic">Sphingorhabdus contaminans</Emphasis> comb. nov.

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated T5^T, was isolated from the Chishui River in Maotai town, Guizhou Province, Southwest of China. Strain T5^T was found to grow optimally at pH 9.0 and 25 °C. The 16S rRNA gene sequence analysis indicated that strain T5^T belongs to the family Sphingomonadaceae within the phylum Proteobacteria; the strain T5^T clustered with the type strains of Sphingopyxis contaminans, Sphingorhabdus wooponensis and Sphingorhabdus rigui, with which it exhibits 16S rRNA gene sequence similarity values of 96.2–96.9%. The DNA G+C content was 58.5 mol%. The major respiratory quinone was Q-10 and the major polar lipid was phosphatidylethanolamine. The major polyamine was homospermidine and the major fatty acids were C_18:1 ω7c (37.5%) and C_16:1 ω7c (30.1%). On the basis of phylogenetic, phenotypic and genetic data, strain T5^T represents a novel species of the genus Sphingorhabdus, for which the name Sphingorhabdus buctiana sp. nov. is proposed. The type strain is T5^T (= CGMCC 1.12929^T = JCM 30114^T). It is also proposed that Sphingopyxis contaminans should be reclassified as a member of the genus Sphingorhabdus.