Identification bacteria associated with Haliclona sp. sponges from Enggano Island, Indonesia with antimicrobial activity against human pathogens

Aims@#Antimicrobial compounds are bioactive compounds that have ability to inhibit microbial growth activities. This study aimed to screen and identify bacteria associated with Haliclona sp. sponges from Enggano Island, Indonesia that had potential to produce antimicrobial compounds against Escherichia coli, Candida albicans and Staphylococcus epidermidis.@*Methodology and results@#The method used to screen and identify bacteria in this study including screening assay, morphological identification, Gram staining and spore staining method, biochemical tests and molecular identification based on 16S rRNA gene. This study resulted 16 isolates which were successfully isolated from Haliclona sp. According to screening assay, 5 isolates could potentially produce antimicrobial compounds coded as HEBS1, HEBS3, HEBS6, HEBB2 and HEBB3. Based on Gram staining, spore staining, biochemical test and molecular identification results, HEBS1 had proximity to Brachybacterium paraconglomeratum, HEBS3 had proximity to Kocuria palustris, HEBS6 had proximity to Psychrobacter pasificensis, HEBB2 had proximity to Bacillus aryabhattai, and HEBB3 had proximity to Bacillus toyonensis.@*Conclusion, significance and impact of study@#From 16 isolates that successfully isolated, there were 5 isolates that could potentially produce antimicrobial compounds against Escherichia coli, Staphylococcus epidermidis and Candida albicans. These isolates can be served as antimicrobial compounds producer. However, identification and purification of these antimicrobial compounds are needed to be done before applied it for medicine in the future.

In Vitro Antibacterial Activities Of Marine Sponge-Associated Bacteria Against Pathogenic Vibrio Spp. Causes Vibriosis In Shrimps

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.

Antiproliferative activity of biomass extract from Pseudomonas cedrina

Background: The study of plant-associated microorganisms is very important in the discovery and development of bioactive compounds. Pseudomonas is a diverse genus of Gammaproteobacteria comprising more than 60 species capable of establishing themselves in many habitats, which include leaves and stems of many plants. There are reports of metabolites with diverse biological activity obtained from bacteria of this genus, and some of the metabolites have shown cytotoxic activity against cancer cell lines. Because of the high incidence of cancer, research in recent years has focused on obtaining new sources of active compounds that exhibit interesting pharmacodynamic and pharmacokinetic properties that lead to the development of new therapeutic agents. Results: A bacterial strain was isolated from tumors located in the stem of Pinus patula, and it was identified as Pseudomonas cedrina. Extracts from biomass and broth of P. cedrina were obtained with chloroform:methanol (1:1). Only biomass extracts exhibited antiproliferative activity against human tumor cell lines of cervix (HeLa), lung (A-549), and breast (HBL-100). In addition, a biomass extract from P. cedrina was fractioned by silica gel column chromatography and two diketopiperazines were isolated: cyclo-(L-Prolyl-L-Valine) and cyclo-(L-Leucyl-L-Proline). Conclusions: This is the first report on the association of P. cedrina with the stems of P. patula in Mexico and the antiproliferative activity of extracts from this species of bacteria against human solid tumor cell lines.

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 IC

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 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.

Impact of microbiota in colorectal carcinogenesis: lessons from experimental models

A role of gut microbiota in colorectal cancer (CRC) growth was first suggested in germ-free rats almost 50 years ago, and the existence of disease-associated bacteria (termed pathobionts) had becoming increasingly evident from experimental data of fecal transplantation, and microbial gavage or monoassociation. Altered bacterial compositions in fecal and mucosal specimens were observed in CRC patients compared to healthy subjects. Microbial fluctuations were found at various cancer stages; an increase of bacterial diversity was noted in the adenoma specimens, while a reduction of bacterial richness was documented in CRC samples. The bacterial species enriched in the human cancerous tissues included Escherichia coli, Fusobacterium nucleatum, and enterotoxigenic Bacteroides fragilis. The causal relationship of gut bacteria in tumorigenesis was established by introducing particular bacterial strains in in situ mouse CRC models. Detailed experimental protocols of bacterial gavage and the advantages and caveats of different experimental models are summarized in this review. The microbial genotoxins, enterotoxins, and virulence factors implicated in the mechanisms of bacteria-driven tumorigenesis are described. In conclusion, intestinal microbiota is involved in colon tumorigenesis. Bacteria-targeting intervention would be the next challenge for CRC.

Assessment of Rice Associated Bacterial Ability to Enhance Rice Seed Germination and Rice Growth Promotion

ABSTRACT The application of beneficial bacteria has recently been used for sustainable agriculture. In current research, 71 bacterial isolates were obtained from rice plant and the rhizosphere soil of different paddy fields in Guilan province, Iran. After primitive investigation, 40 bacteria with typical predominant characteristics were selected. By PCR-RFLP of their 16S r-DNA gene, 8 Operational Taxonomic Units (OTUs) totally consisted of 33 isolates were obtained. From all of them, 8 isolates were selected for rice seed germination experiment, then, effective isolates were used for pot experiment to evaluate their ability for promoting rice growth. All of them were able to increase rice growth and yield, but in different potential. These tested isolates were identified as Alcaligenes faecalis (DEp8, O1R4), Pantoea ananatis (AEn1), Bacillus vietnamensis (MR5), Bacillus idriensis (MR2) and Stenotrophomonas maltophilia by partial sequencing of their 16S r-DNA gene. Among them, AEn1 and MR5 produced indole-3- acetic acid (IAA) in larger amounts than the other isolates and the isolates AEn1 and O1R4 were able to solubilize phosphate in higher amounts. According to the results obtained, it can be concluded that AEn1, O1R4 and MR5 can be considered as bacterial inoculants to use as alternatives for chemical fertilizers.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria

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.

Research Advance on Diketopiperazines Produced by Marine Microorganism / 微生物学通报

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.