Cultivable Sponge-Associated Actinobacteria from Coastal Area of Eastern Mediterranean Sea

In this study, 16 marine sponge samples collected from Eastern Mediterranean Sea were used for the isolation of sponge-associated Actinobacteria. Different media and pre-treatment methods were applied for the isolation experiments. In total, 7578 actinomycetes colonies were observed on the primary isolation plates, and 20 representative isolates were selected for further studies based on their morphologies and chemical profiles. These isolates were investigated for their antimicrobial activities, seawater requirements and 16S rRNA gene sequences. The phylogenetic analysis revealed that 80% of the isolated Actinobacteria was a member of the Streptomyces genus. All the isolates showed no absolute requirement for seawater. Fifteen of the selected isolates exhibited antimicrobial activity against methicillin resistant Staphylococcus aureus and vancomycin resistant Enterococcus faecium, whereas 3 isolates were active against Candida albicans.

Sponge-associated bacteria of Lakshadweep coral reefs, India: resource for extracellular hydrolytic enzymes

Sponges (Phylum: Porifera) is one of the major groups in the Lakshadweep coral reefs. These sponges harbor diverse bacteria with metabolic potentiality. From biodiversity to biotechnological prospecting, scientific investigations related to sponge associated microorganisms have expanded, but remain rather limited to few geographic locations. In this study, culturable bacteria associated with two demosponges viz Dysidea granulosa, Sigmadocia fibulata and the ambient water were screened for commercially important enzymes such as amylase, protease, gelatinase, lipase, deoxyribonucleic, phosphatase and urease. Amylase and phosphatase were the predominant enzymes produced by >80% of sponge-associated bacteria compared to the ambient water. Nearly 50% of the sponge-associated bacteria expressed multiple enzymatic activities (> 4) with variation in the percentage of expression of individual enzymes. More than 65% of the culturable heterotrophic bacteria associated with sponges were Gammaproteobacteria. The order Vibrionales was the main source for multiple enzyme production. Sponge associated bacteria formed more closely related clusters than the water isolates based upon their activity pattern. High recovery of sponge-associated bacteria with multiple enzymatic activities suggest that these versatile bacteria are yet unexploited potential for bioprospecting.

Bacillus sp. SAB E-41-derived extract shows antiaging properties via ctt1-mediated oxidative stress tolerance response in yeast Schizosaccharomyces pombe

Objective: To analyze potential activation of oxidative stress tolerance systems by SAB E-41 bacterial extract in promoting the life span of yeast Schizosaccharomyces pombe. Methods: In vitro analysis was done to assess antioxidant activity of SAB E-41 bacterial extract. Antiaging property of the particular extract was then assayed through spot test and chronological life span assays. Furthermore, sty1 mitogen-activated protein kinase, pap1 transcriptional factor of oxidative stress response and its downstream genes, ctt1 were evaluated via real time PCR. The protein level of ctt1 was then observed via Western Blot analysis. In addition, accumulation of reactive oxygen species and mitochondrial activity were conducted to understand the effect of SAB E-41 upon oxidative stress response systems in vivo. Results: The IC50 values of corresponding extract for antioxidant(DPPH; ABTS) and antiglycation were 402.40, 358.13 and 683.55 μg/mL, respectively. In addition, SAB E-41 extract(750 μg/mL) exhibited antiaging properties, which could be attributed to significant up-regulation of oxidative stress response genes, sty1, pap1 and ctt1. Interestingly, SAB E-41 extract could enhance stress tolerance phenotype of Schizosaccharomyces pombe against H2 O2-induced oxidative stress. These results were supported by increasing mitochondrial activity and reactive oxygen species intracellular levels. Conclusions: SAB E-41 extract could promote yeast life span likely via up-regulation of oxidative stress responses in yeast. Our results suggest that adaptive response via up-regulation of oxidative stress transcriptional factors, and its downstream gene, ctt1, as well as mitochondrial activity contributes in combating oxidative stress thus promoting yeast life span.

The antibacterial capacity of marine bacteria isolated from sponge Acanthella cavernosa collected from Lombok Island

Objective:To find a potent antibiotic producer from the sponge-associated bacteria as well as to profile the important substances.Methods:Sponge collection,bacteria isolation,extraction and characterization of potent active compounds were carried out for this study.Results:Approximately 59 single strains of bacteria were isolated from this sponge.Totally 40 strains showed activity against Escerichia coli,Staphylococcus aureus and Vibrio eltor.The chemical separation of the potent strain Bacterium sp.Lb.10%.2.1.1.b,using n-phase column chromatography revealed 7 active fractions(7,8,9,10,11,14 and 15).The gas chromatography-mass spectrometer analysis of Fraction 7 indicated some phenolic compounds including 4-nonylphenol,methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,acetosyringone,2,4-bis(1-phenylethyl)phenol,1,2-benzenedicarboxylic acid,mono(2-ethylhexyl)ester,tri(2-ethylhexyl)trimellitate and oleamide.Conclusions:Indeed,this is a preliminary information in profiling chemical substances,produced by Bacterium sp.Lb.10%.2.1.1.b.Further purification and structural chemical determination were needed to find a comprehensive result.