Biosurfactant-Producing Bacillus velezensis PW192 as an Anti-Fungal Biocontrol Agent against Colletotrichum gloeosporioides and Colletotrichum musae

In this study, plant-root-associated Bacillus species were evaluated as antifungal biocontrol agents by analyzing the production of surface bioactive molecules known as lipopeptide biosurfactants. This study aimed to isolate and characterize antifungal biosurfactant-producing Bacillus bacterium. Bacillusvelezensis PW192 was isolated from the rhizosphere of Lagerstroemia macrocarpa var macrocarpa and identified based on phylogenetic analysis of the 16S rRNA gene. The biosurfactant was excreted to cultured supernatant and exhibited emulsification power up to 60% and a decrease in surface tension from 72 in distilled water to 21 mN/m. The surface tension properties were stable in a broad range of pH from 6 to 10, in high temperatures up to 100 °C, and in salinities with a NaCl concentration up to 12% (w/v). Starting from 0.5 mg of acid, precipitated crude biosurfactant exhibited antifungal activity toward Anthracnose, caused by the phytopathogens Colletotrichum gloeosporioides and C. musae. The chemical structures of the biosurfactant were structurally characterized as lipopeptides fengycin A and fengycin B. The stability of the biosurfactant, as well as the antifungal properties of B. velezensis PW192, can potentially make them useful as agricultural biocontrol agents, as well as in other biotechnological applications

Randomized Controlled Trial of Bisacodyl Suppository Versus Placebo for Postoperative Ileus After Elective Colectomy for Colon Cancer

ObjectiveTo compare the use of bisacodyl suppository with placebo in resolving postoperative ileus after elective colectomy in a randomized controlled trial.MethodsTwenty elective colectomy patients were randomized to receive either bisacodyl or placebo suppository on the third postoperative day. Outcomes included time to first defaecation, length of hospital stay, and postoperative complications. Participants and the primary investigator were unaware of the treatment assignment.ResultsAll 10 participants in the bisacodyl group defaecated on the third postoperative day, while participants in the placebo group defaecated on days 3 (2/10), 4 (5/10) and 5 (3/10) (p < 0.001). The average lengths of hospital stay for the bisacodyl and placebo groups were 8.5 ± 2.7 days and 10.4 ± 5.3 days, respectively (p = 0.325). No significant complications occurred in either group.ConclusionBisacodyl suppository seems to be effective and safe in resolving postoperative ileus after elective colectomy in colon cancer patients

Saccharopolyspora rhizosphaerae sp. nov., an actinomycete isolated from rhizosphere soil in Thailand

Intra, Bungonsiri, Euanorasetr, Jirayut, Také, Akira, Inahashi, Yuki, Mori, Mihoko, Panbangred, Watanalai, Matsumoto, Atsuko (2019): Saccharopolyspora rhizosphaerae sp. nov., an actinomycete isolated from rhizosphere soil in Thailand. International Journal of Systematic and Evolutionary Microbiology 69 (5): 1299-1305, DOI: 10.1099/ijsem.0.003307, URL: http://dx.doi.org/10.1099/ijsem.0.00330

Thailandins A and B, New Polyene Macrolactone Compounds Isolated from Actinokineospora bangkokensis Strain 44EHW^T, Possessing Antifungal Activity against Anthracnose Fungi and Pathogenic Yeasts

Two new polyene macrolactone antibiotics, thailandins A, <b>1</b>, and B, <b>2</b>, were isolated from the fermentation broth of rhizosphere soil-associated Actinokineospora bangkokensis strain 44EHW^T. The new compounds from this strain were purified using semipreparative HPLC and Sephadex LH-20 gel filtration while following an antifungal activity guided fractionation. Their structures were elucidated through spectroscopic techniques including UV, HR-ESI-MS, and NMR. These compounds demonstrated broad spectrum antifungal activity against fungi causing anthracnose disease (Colletotrichum gloeosporioides DoA d0762, Colletotrichum gloeosporiodes DoA c1060, and Colletotrichum capsici DoA c1511) as well as pathogenic yeasts (Candida albicans MT 2013/1, Candida parasilopsis DKMU 434, and Cryptococcus neoformans MT 2013/2) with minimum inhibitory concentrations ranging between 16 and 32 μg/mL. This is the first report of polyene antibiotics produced by Actinokineospora species as bioactive compounds against anthracnose fungi and pathogenic yeast strains