Characterization and Isolation of Peptide Metabolites of an Antifungal Bacterial Isolate Identified as Bacillus Amyloliquefaciens Subspecies Plantarum Strain Fzb42

Abstract

Some bacteria produce antimicrobial chemicals in their immediate environments. These antimicrobial agents are enzymes, polypeptides or non-protein organic compounds. In this study, a bacterial isolate that produces antifungal chemical(s) was isolated from an over incubated nutrient agar plate that was exposed to air. The bacterium is aerobic, Gram positive bacilli; capsule and endospore producing. It ferments glucose and sucrose but not lactose, galactose, mannitol and sorbitol; it is citrate, indole, methyl red and Voges Prauskauer negative. Using agar gel diffusion technique, the cell-free culture supernatant resulting from centrifugation of a six day bacterial culture showed antifungal activity against filamentous fungi but not yeasts. Heating the cell-free supernatant in 90 ˚C water bath and digestion with different proteases had no negative impact on the antifungal activity. A segment of 16S rRNA gene of the bacterial isolate was amplified. The nucleotide sequence of the amplicon was used to identify the bacterium as being very similar to Bacillus amyloliquefaciens subsp. plantarum strain FZB42. Five bacterial peptides were isolated and identified from cell free supernatant of the bacterial culture using a suite of techniques, including flash chromatography, HPLC, NMR and mass spectrometry. One of the five peptides has been previously reported in literature to possess antifungal activity.

Antibiotic Activity Altered by Competitive Interactions Between Two Coral Reef–Associated Bacteria

“…Targeted interaction assays with the environmental isolates nearest the antibiotic-producing isolate established that the isolate (Paracoccus sp., strain CA-113-2) to the left of the antibiotic producer (Streptomyces sp., strain CC-108-1) was not stimulating antibiotic production by the antibiotic-producing isolate (c, i), but rather that the yellow isolate to the right of the antibiotic-producer (Agrococcus sp., strain CA-87-1) was responsible for impairing its ability to inhibit MRSA growth (c, iii). The antibioticproducing isolate also affected the growth of a lawn of the marine bacterium Bacillus oceanisediminus (d) of spectroscopic data to data previously reported for diketopiperazines in the literature, including HRMS and comparison of NMR 1 H and 13 C chemical shifts, supported structural assignments of cyclo(Leu-Pro), cyclo(Phe-Pro), and cyclo(Gly-Pro) [37][38][39][40]. Additional NMR data, including H-H couplings via COSY and C-H couplings via HSQC and HMBC, were used to further confirm the structural assignment.…”

Characterization and Diversity of plant growth promoting Endophytic and Rhizosphere Bacteria isolated from theRhizosphere and tissues of Pepper and their effect on plant growth promotion and disease suppression of Phytophthora capsici

“…Bacillus amyloliquefaciens also, have been reported as both plant growth promoters and biocontrol agents against soilborne pathogens including Fusarium wilt of banana and potato dry rot caused by Fusarium sp. 45 . In our study 20 isolates showed both plant growth promotors and biological controls against P. capsici.…”

Identification of Soil Bacterial Isolates Suppressing Different Phytophthora spp. and Promoting Plant Growth

“…B. amyloliquefaciens and B. velezensis have been widely reported as plant growth promoters and biocontrol agents against a broad range of soil-borne pathogens including Fusarium wilt of banana and potato dry rot caused by Fusarium sp. ( Recep et al, 2009 ; Wang et al, 2013 ; Xu et al, 2013 ; Meng et al, 2016 ; Adibi et al, 2017 ). A recent study showed that B. velezensis had a broad-spectrum biocontrol activity via antagonism against two foliar bacterial pathogens and soil-borne fungal pathogens ( Liu et al, 2017 ).…”