Caprellid assemblages (Crustacea: Amphipoda) in shallow waters invaded by <Emphasis Type="Italic">Caulerpa racemosa</Emphasis> var. <Emphasis Type="Italic">cylindracea</Emphasis> from southeastern Spain

Growth of the invasive algae Caulerpa racemosa var. cylindracea in shallow habitats may influence the faunal assemblage composition. We studied its effects on caprellid assemblages associated with shallow-water habitats of hard and soft bottoms from the SE Iberian Peninsula (native rocky-bottom algae, C. racemosa from hard and soft bottoms, and Caulerpa prolifera, Cymodocea nodosa and Posidonia oceanica from soft bottoms). Samples were taken in two different sampling periods (September 2004 and March 2005). A total of seven caprellid species were identified, with important differences in their distribution in different habitats. Total abundance of caprellids was very high in March on native algae on hard bottoms, and on C. racemosa on both soft and hard bottoms. On both hard and soft bottoms, abundances of Caprella hirsuta recorded from C. racemosa were low. On the other hand, a higher abundance of other species, namely C. acanthifera, C. santosrosai, Phtisica marina and Pseudoprotella phasma, was recorded from C. racemosa. The results indicate that C. racemosa may have a positive influence on some caprellid species, while seasonal changes are also evident. It is concluded that introduced C. racemosa may serve as a new habitat, promoting and maintaining caprellid populations in shallow Mediterranean habitats.     

Sexual and asexual colony foundation and the mechanism of facultative parthenogenesis in the termite <Emphasis Type="Italic">Reticulitermes speratus</Emphasis> (Isoptera,Rhinotermitidae)

Summary. Facultative parthenogenesis has great adaptive significance, especially with regard to low pairing efficiency. In the termite Reticulitermes speratus, females that fail to mate with males reproduce parthenogenetically and found colonies cooperatively with partner females or even alone. Comparison of colony foundation success at 400 days between colonies founded by single females (F), female-female pairs (FF), and male-female pairs (FM) showed that female-female cooperation promoted colony survivorship over monogamous foundation. We report here for the first time the mode of parthenogenesis in Isoptera. Combining chromosome observations and genetic analysis using microsatellites, we show that the mode of parthenogenesis is diploid thelytoky and that the restoration of ploidy is most likely accomplished by terminal fusion. Parthenogens show a higher mortality and a longer egg-development time than sexually produced offspring, probably due to reduced heterozygosity. In addition Wolbachia bacteria were detected in R. speratus. However, since Wolbachia was also detected in non-parthenogenetic R. flavipes, it is unlikely that Wolbachia is the cause of parthenogenesis in R. speratus.Received 30 October 2003; revised 4 March 2004; accepted 17 March 2004.     

Production of an anti-fungal substance for biological control of <Emphasis Type="Italic">Phytophthora capsici</Emphasis> causing phytophthora blight in red-peppers by <Emphasis Type="Italic">Streptomyces halstedii</Emphasis>

The culture broth of Streptomyces halstedii AJ-7 suppressed the growth of Phytophthora capsici, which causes phytophthora blight in red-peppers, with less than 1% survival of the pathogen after 12 h of treatment. The low molecular fraction ( 10 kDa) of the culture broth retained anti-fungal activity against P. capsici after being held at 100 °C for 6 h.Revisions requested/26 August 2004; Revisions received 16 August 2004/10 December 2004     

Phytochemical, antimicrobial, antioxidant and antigenotoxic potentials of Cyperus rotundus extracts

The aqueous, ethyl acetate, methanolic and Total Oligomer Flavonoids (TOF) enriched extracts, obtained from the aerial parts of Cyperus rotundus, were investigated for their contents in phenolic compounds. Antioxidative activity using the NBT/riboflavin assay system, antimicrobial activity against Gram positive and Gram negative bacterial reference strains as well as antigenotoxic activity tested with the SOS chromotest assay were also studied. Significant antibacterial activity against reference strains; Staphylococcus aureus, Enterococcus faecalis, Salmonella enteritidis and Salmonella typhimurium, was detected in the presence of ethyl acetate and TOF enriched extracts. In addition to their antimicrobial activity, the same extracts showed a significant ability to inhibit nitroblue tetrazolium reduction by the superoxide radical in a non enzymatic O₂^.− generating system, and were also able to reduce significantly the genotoxicity induced by nifuroxazide and Aflatoxin B1. The antioxidant, antimicrobial and antigenotoxic activities exhibited by C. rotundus depend on the chemical composition of the tested extracts.     

Biofilm formation in an ice cream plant

The sites of biofilm formation in an ice cream plant were investigated by sampling both the production line and the environment. Experiments were carried out twice within a 20-day period. First, stainless steel coupons were fixed to surfaces adjacent to food contact surfaces, the floor drains and the doormat. They were taken for the analysis of biofilm at three different production stages. Then, biofilm forming bacteria were␣enumerated and also presence of Listeria monocytogenes was monitored. Biofilm forming isolates were selected on the basis of colony morphology and Gram’s reaction; Gram negative cocci and rod, Gram positive cocci and spore forming isolates were identified. Most of the biofilm formations were seen on the conveyor belt of a packaging machine 8 h after the beginning of the production, 6.5 × 10³ cfu cm⁻². Most of the Gram negative bacteria identified belong to Enterobacteriaceae family such as Proteus, Enterobacter, Citrobacter, Shigella, Escherichia, Edwardsiella. The other Gram negative microflora included Aeromonas, Plesiomonas, Moraxella, Pseudomonas or Alcaligenes spp. were also isolated. Gram positive microflora of the ice cream plant included Staphyloccus, Bacillus, Listeria and lactic acid bacteria such as Streptococcus, Leuconostoc or Pediococcus spp. The results from this study highlighted the problems of spread of pathogens like Listeria and Shigella and spoilage bacteria. In the development of cleaning and disinfection procedures in ice cream plants, an awareness of these biofilm-forming bacteria is essential for the ice cream plants.     

Diet of the invasive piscivorous fish <Emphasis Type="Italic">Fistularia commersonii</Emphasis> in a recently colonized area of the eastern Mediterranean

The composition of the diet of the Indo-Pacific cornetfish Fistularia commersonii from the SE Aegean Sea is described. The stomach contents of 245 specimens collected between September 2004 and March 2005 were examined. Dietary comparisons were made reflecting the relationship between diet composition, time of year, and fish size. Correlation between predator length and prey length was significant. The diet of the blue cornetfish consists of 96% by number and 99.95% by weight of fish. Size classification and habitat of prey groups (benthic, supra-benthic, and pelagic) showed that with increased body length the blue cornetfish extended its diet to larger prey and more generalist feeding. Spicara smaris, Boops boops, and Mullidae spp. were the most abundant prey by weight whereas a variety of small benthic fish (especially gobiids) and newly hatched fish constituted the largest number of prey items. Length–weight relationships for the cornetfish were investigated.     

Dynamics of potentially harmful microalgae in a confined Mediterranean Gulf—Assessing the risk of bloom formation

The population dynamics of potentially harmful microalgae was investigated in the semi-enclosed shallow Gulf of Kalloni, Greece (Aegean Sea, Eastern Mediterranean), during a 2-year period from August 2004 to March 2006. A total of 21 potentially harmful microalgae (bloom-forming and/or toxic) were identified including 3 diatoms and 18 dinoflagellates. The densities of each species were analyzed in time and space and in relation to environmental parameters. Some species such as Alexandrium insuetum, Heterocapsa circularisquama, Karlodinium veneficum, Scrippsiella trochoidea, and Ceratium spp. developed high cell concentrations, particularly during a Pseudo-nitzschia calliantha winter bloom. Other species such as Dinophysis caudata, Ostreopsis ovata, Prorocentrum minimum, and Protoperidinium crassipes were rare or appeared in small numbers. Densities of the most abundant species were closely associated with freshwater nutrient-rich inputs during winter, being negatively correlated with temperature and salinity and positively correlated with nitrogen. The spatial distribution of the abundant species exhibited a marked increase towards the inner part of the gulf, close to the main freshwater inputs, whereas some species were mainly concentrated in the dilute surface layer (1 m depth). Examination of the abundance–occupancy relationship revealed that the species more prone to bloom are those with wide spatial distribution and frequent presence throughout the year such as the diatom P. calliantha. Although blooms of cyst-forming species are rarer, an increased risk can be foreseen under favorable resource supply and environmental conditions during winter.     

Nesting biology of the fungus growing ants <Emphasis Type="Italic">Mycetarotes</Emphasis> Emery (Attini,Formicidae)

Summary. Fungus-growing ants of the genus Mycetarotes are among the least studied in the tribe Attini. This report documents nest architecture and worker population numbers for 19 nests of M. parallelus and 5 nests of M. acutus, including the first such report for M. acutus. This new information is integrated with the scant biological information reported on Mycetarotes to date. The resulting picture of Mycetarotes life history, as well as the relative ease with which large numbers of nests can be collected and observed in the field, suggest that Mycetarotes (particularly M. parallelus) is an ideal model system for the study of coevolution of lower-attine ants and their cultivated fungi.Received 30 June 2003; revised 17 December 2003; accepted 23 March 2004.     

A simplified method for assay of hydrogenase activities of H<Subscript>2</Subscript> evolution and uptake in <Emphasis Type="Italic">Enterobacter aerogenes</Emphasis>

Assay of hydrogenase activity pertaining to H₂ production needs anaerobic conditions. To establish a simplified method for assay of hydrogenase activities by using intact cells of Enterobater aerogenes, different chemicals capable of enhancing the cell-wall permeability to electron mediators were examined. As a result, Triton X-100 and CTAB were found to be appropriate for H₂ uptake and evolution activities of the intact cells, respectively. This method enabled H₂ uptake and evolution activities of the intact cells to be easily detected. This is also the first report of the presence of H₂ uptake hydrogenase activity in E. aerogenes.Revisions requested 2 March 2005 and 21 April 2005; Revisions received 12 April 2005 and 17 May 2005     

Thermostable cellulases from <Emphasis Type="Italic">Streptomyces</Emphasis>sp.: scale-up production in a 50-l fermenter

Thermostable cellulase was produced by Streptomyces sp. T3-1 grown in a 50-l fermenter. Maximum cellulase activity was attained on the fourth day when agitation speeds and aeration rates were controlled at 300 rpm and 0.75 vvm, respectively. Maximum enzyme activities were: 148 IU CMCase ml^–1, 45 IU Avicelase ml^–1, and 137 IU -glucosidase ml^–1 with productivity of 326 IU l^–1 h^–1, which were 10--32% higher than the values obtained in shake-flask culturesRevisions requested 12 October 2004/1 November 2004; Received received 1 November 2004/14 December 2004     

Colony structure and sex allocation ratios in the ant <Emphasis Type="Italic">Temnothorax crassispinus</Emphasis>

Summary. We analyzed the impact of ecological parameters, such as nest density and nest site availability, on colony organization and investment patterns in two populations of the ant Temnothorax crassispinus, a parapatric sibling species of the well-studied T. nylanderi (Temnothorax was until recently referred to as Leptothorax (Myrafant); Bolton, 1993). As in T. nylanderi, sex allocation ratios were strongly associated with total sexual reproduction, i. e., nests with large sexual investment produced mainly female sexuals. Furthermore, nest site quality affected sex allocation ratios, with colonies from ephemeral nest sites producing a more male-biased sex allocation ratio than colonies from sturdy nest sites. In contrast to T. nylanderi, workers in colonies of T. crassispinus were mostly fullsisters both in a dense and a sparsely populated area, suggesting that colony fusion and colony usurpation are rare in this species. In addition, the presence of a queen in a local nest unit strongly influenced sex ratio decisions, in that these nests raised a more male biased allocation ratio compared to queenless nests. This also suggests that colony structure is more stable in T. crassispinus than in T. nylanderi. We conclude that sibling species, though often very similar in their morphology and ecological requirements, may nevertheless react very differently to ecological variation.Received 11 December 2003; revised 4 March 2004; accepted 19 April 2004.     

Isolation and characterization of <Emphasis Type="Italic">Azotobacter</Emphasis> and <Emphasis Type="Italic">Azospirillum</Emphasis> strains from the sugarcane rhizosphere

Bacteria with the ability to grow on nitrogen-free media and with nitrogenase activity under aerobic or microaerobic conditions were isolated from sugarcane roots collected from four different agricultural locations in Granada (Spain). Isolates were Gram negative rods and were identified as Azotobacter chroococcum and Azospirillum brasilense. Our results suggest that Azotobacter isolates do not have a particular affinity for sugarcane rhizospheres and that, on the contrary, Azospirillum isolates show specific association and perhaps endophytic colonization of sugarcane. However, obligate endophytes (Gluconacetobacter diazotrophicus) were not found in the apoplastic fluid of the stems and macerates extracts of sugarcane tissues with the procedure applied. Population of this microorganism might be in low number in the Spanish sugarcane varieties studied which is also discussed.     

Ethanol production from cellulosic materials by genetically engineered <Emphasis Type="Italic">Zymomonas mobilis</Emphasis>

To confer the ability to ferment cello-oligosaccharides on the ethanol-producing bacterium, Zymomonas mobilis, the -glucosidase gene from EmRuminococcus albus, tagged at its N-terminal with the 53-amino acid Tat signal peptide from the periplasmic enzyme glucose–fructose oxidoreductase from Z. mobilis, was introduced into the strain. The tag enabled 61% of the -glucosidase activity to be transported through the cytoplasmic membrane of the recombinant strain which then produced 0.49 g ethanol/g cellobiose. Revisions requested 9 November 2004; Revisions received 10 December 2004; Accepted 13 December 2004     

Prevalence of different outer membrane proteins in isolates of <Emphasis Type="Italic">Aeromonas</Emphasis> species

Outer membrane proteins (Omps) are located at host–bacterial interface and are important for host immune responses and as targets for drug therapy. In the present study, outer membrane protein profiling of 40 isolates of Aeromonas spp. (A. hydrophila, A. trota, A. caviae, A. veronii biovar sobria, A. jandaei and A. schubertii) obtained from different sources was done using SDS-PAGE, PCR and Western blotting techniques. The 3–4 high intensity bands at the region of 25–45 kDa were obtained in all the isolates with minor differences. Twenty Omp patterns (M1–M20) were obtained. The isolates were further tested for omp specific PCR and Omp specific antibody based Western blot. Positive reaction was obtained in 35 isolates of Aeromonas using ompTS-PCR and anti-OmpTS antibodies based Western blot. Primers specific for omp48 and antibodies to Omp48 reacted with 32 isolates. One mutant of A. hydrophila (AB-3-5-2 mutant) and 4 clinical isolates (one A. jandaei and three A. schubertii) were negative for both the genes. When both the assay systems were tested with bacterial cultures other than Aeromonas spp., anti-OmpTS antibodies were specific for Aeromonas spp. whereas, the anti-omp48 antibodies gave reaction with Escherichia coli and other Gram negative non-aeromonads. From the results we conclude the usefulness of OmpTS for identification of virulent Aeromonas spp. and Omp48 as a potential recombinant vaccine candidate for Gram negative opportunistic infection of fish. Omp profiling can be a useful molecular marker for characterizing Aeromonas isolates.     

<Emphasis Type="Italic">Exiguobacterium acetylicum</Emphasis> strain 1P (MTCC 8707) a novel bacterial antagonist from the North Western Indian Himalayas

Exiguobacterium acetylicum strain 1P (MTCC 8707) is a rhizospheric, Gram positive, rod shaped, yellow pigmented bacterium isolated from an apple orchard rhizospheric soil, on nutrient agar plates incubated at 4°C. The species level identification was arrived on the basis of 16S rRNA gene sequencing. The sequence showed 98% similarity with sequences of E. acetylicum available in the public domain. The strain was positive for siderophore and HCN production. In separate invitro assays it was found to inhibit the growth and development of Rhizoctonia solani, Sclerotium rolfsii, Pythium and Fusarium oxysporum. The volatile compound produced by the bacterium was found to be the most potent in inhibiting the hyphal development of R. solani, S. rolfsii, Pythium and F. oxysporum by 45.55, 41.38, 28.92 and 39.74% respectively. Commonly observed deformities caused by the diffusible and volatile compounds produced by the bacterium included hyphal inhibition, constriction and deformation. Under pot culture conditions the bacterium improved the germination and early growth parameters of pea (Pisum sativum) in the presence of R. solani and S. rolfsii.     

Copper Oxide Nanomaterials Derived from Zanthoxylum armatum DC. and Berberis lycium Royle Plant Species: Characterization,Assessment of Free Radical Scavenging and Antibacterial Activity

Copper oxide nanomaterials were synthesized by a facile sustainable biological method using two plant species (Zanthoxylum armatum DC. and Berberis lycium Royle ). The formation of materials was confirmed by FT‐IR, ATR, UV‐visible, XRD, TEM, SEM, EDX, TGA and PL. The antibacterial activity was evaluated by agar well diffusion method to ascertain the efficacy of plant species extract and extract derived copper oxide nanomaterials against six Gram‐positive bacteria namely Staphylococcus aureus, Streptococcus mutans, Streptococcus pyogenes, Corynebacterium diphtheriae, Corynebacterium xerosis, Bacillus cereus and four Gram‐negative bacteria such as Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris against the standard drug, Ciprofloxacin for Gram‐positive and Gentamicin for Gram‐negative bacteria, respectively. In both cases, copper oxide nanomaterials were found to be sensitive in all the bacterial species. Sensitivity of copper oxide nanomaterials shows an be higher as compared to plant species extract against different bacteria. Scavenging activity of plant extracts along with nanomaterials have been accessed using previously reported protocols employing ascorbic acid as standard. Scavenging activity of copper oxide nanomaterials shows an increase with increase in concentration. The biological activity (bactericidal and scavenging efficiency) of plant derived copper oxide nanomaterials revealed that these materials can be used as potent antimicrobial agent and DPPH scavengers in industrial as well as pharmacological fields.     

1β,7β-Dihydroxydehydroabietic acid,a new biotransformation product of dehydroabietic acid by Aspergillus niger

Microbial transformation of dehydroabietic acid by Aspergillus niger afforded the new derivative 1β,7β-dihydroxydehydroabietic acid and the known 1β-hydroxy and 7β-hydroxy derivatives. The structures were elucidated by spectroscopic methods. The compounds were assessed towards Gram (+) and Gram (−) bacteria and showed a weak antimicrobial effect. This revised version was published online in August 2006 with corrections to the Cover Date.     

In vitro and in vivo activity of extracts from the soft coral <Emphasis Type="Italic">Lobophytum pauciflorum</Emphasis> on trophozoites of <Emphasis Type="Italic">Entamoeba histolytica</Emphasis>

Methanolic extracts from the marine coral Lobophytum pauciflorum exhibited an in vitro amebicidal activity against trophozoites of Entamoeba histolytica and were found to cure caecal amoebiasis in 85% of infected rats. This activity was restricted to the n-butanol fraction, from which three pure compounds were isolated.Original Russian Text Copyright © 2004 by Biologiya Morya, Ghoshal, Lakshmi.     

Abundance of drifting seaweeds in eastern East China Sea

Drifting seaweeds play important ecological roles in offshore waters. Recently, large amounts of drifting seaweed rafts were found in the eastern East China Sea between the continental shelf and the oceanic front of the Kuroshio Current. However, so far there have been no quantitative reports about this particular area. Two research cruises were organized to survey abundance and standing crop of drifting seaweeds in eastern East China Sea in May 2002 and March 2004, using visual census and net sampling of drifting seaweeds. Visual census data were composed of drifting seaweed raft diameter, perpendicular distance from the transect (navigation course of the research vessel) to the raft, and positions. Using these data, we calculated the “effective stripe width” using the DISTANCE software. Drifting seaweed abundance (composed exclusively of Sargassum horneri) in waters located between the continental shelf peripheral area and the Kuroshio oceanic front was estimated to be higher than in any other area within eastern East China Sea in March and May. Abundance means in May 2002 and March 2004 were 6.14 and 29.05 rafts km⁻², respectively, while standing crop reached 126.81 and 20.35 kg km⁻² (wet weight). Mean diameter and drifting seaweed rafts in May 2002 were significantly greater than in March 2004, reflecting seasonal growth of Sargassum horneri.