ABSTRACT
Objective: This study was aimed to isolate and screen marine sponge-associated bacteria producing anti-Vibrio compounds and to identify their compounds from the bacterial extract. Methods: Sponge-associated bacteria were isolated by spread plate method. Their anti-Vibrio activity against Vibrio parahaemolyticus, V. harveyi, and V. vulnificus was determined by dual culture test. Three potential isolates were identified based on 16S-rRNA gene analysis. All isolates producing anti-Vibrio compounds was tested for their haemolytic characters in blood agar medium. Anti-Vibrio activity of the most potential isolate was also tested by using its supernatant, extract, and concentrated culture. Chemical composition of crude extract derived from that isolate was identified by GC-MS analysis. Results: 68 bacterial isolates have been isolated from the marine sponge, Spongia sp., Svenzea sp., Ircinia sp., and Igernella sp. Of 68 isolates, 15 (22%) isolates had anti-Vibrio activities in various spectra against three Vibrio species, including V. harveyi, V. parahaemolyticus, and V. vulnificus. All isolates producing anti-Vibrio compounds were non-haemolytic. Bacterial isolates coded as D6.6, D6.19, and P4.17 have broad spectra. They could inhibit at least two Vibrio species as indicated by the clear zone formed around bacterial colonies. Based on 16S-rRNA, these isolates were closely related (similarity ≥ 99%) to Brevibacterium casei strain M Sw oHS, Bacillus altitudinis strain FJAT 47750, and Bacillus altitudinis strain PgBe190, respectively. D6.6 isolate was the most potential isolate, which could inhibit three Vibrio species. Consistently, its anti-Vibrio activity also confirmed by their supernatant, concentrated culture, and crude extract of that isolate. The crude extract derived from this isolate contained 10 major compounds that are biologically active. Conclusion: This study suggests that 15 bacteria strains isolated from marine sponges were potentially could inhibit Vibrio’s growth in vitro. These isolate could be further explored as anti-Vibrio agent.
ABSTRACT
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 H2O2-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.
ABSTRACT
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 IC
ABSTRACT
Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.
Subject(s)
Animals , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Porifera/microbiology , Pseudomonas putida/chemistry , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/isolation & purification , Microbial Sensitivity Tests , Oceans and Seas , Phylogeny , Pseudomonas putida/genetics , Pseudomonas putida/isolation & purification , Random Amplified Polymorphic DNA Technique , RNA, Bacterial/genetics , /geneticsABSTRACT
The basical structure of diketopiperazines is a cyclic dipeptide condensed by two amino acids. Because of the stable framework of the six-member ring structure, and having two hydrogen bond donor and two hydrogen bond receptor, DKPs have become important chemical pharmacophores, with strong biological activities and pharmacological activities in the drug. A series of cyclic compounds were found from marine organisms in recent years, research showed that their functions are not limited on anti-bacterial, cytotoxic activity, and so on, but also playing an important role in regulatory mechanism of quorum sensing as signal molecules, they have become research hot point in ecological chemistry. This paper reviewed the research progress of diketopiperazines found in the marine microbial metabolites, and the future study trends was discussed and outlooked.