Culture conditions that influence accumulation of zwittermicin A by Bacillus cereus UW85

Abstract

Bacillus cereus strain UW85 produces an antibiotic, designated zwittermicin A, that is associated with the ability of UW85 to suppress damping-off disease of alfalfa (Medicago sativa) caused by the oomycete pathogen, Phytophthora medicaginis, in a laboratory bioassay. We have identified certain culture conditions that promote or suppress zwittermicin A accumulation by UW85. Maximum accumulation was detected in supernatants of trypticase soy broth cultures after sporulation, which is when cultures of UW85 provide the greatest suppression of damping-off on alfalfa. Inorganic amendments to trypticase soy broth cultures had the following effects on zwittermicin A accumulation and disease suppression: phosphate (50 mM or more) reduced zwittermicin A accumulation and disease suppression; ferric iron (0.25-1.0 mM) enhanced zwittermicin A accumulation and disease suppression; micronutrients (manganese, boron, copper, molybdenum, zinc) had no effect on zwittermicin A accumulation or disease suppression. Cultures of UW85 grown in chemically defined minimal medium supplemented with casein hydrolysate or grown in defined medium containing the minimal requirements for growth supplemented with five amino acids (Gln, Arg, Met, Phe, Ile) accumulated zwittermicin A.(ABSTRACT TRUNCATED AT 250 WORDS)

Batch and fed-batch fermentation of Bacillus thuringiensis using starch industry wastewater as fermentation substrate

“…which could be produced by Btk at different concentrations in fermented broth of batch fermentation and fed-batch fermentation with one feed. In fact, Zwitttermicin is known to be produced and depended on the medium components [19]. It is also known that Btk HD-1 (the strain used in this research) can produce Zwittermicin A [20].…”

Application of antagonistic rhizobacteria for control of Fusarium seedling blight and basal rot of lily

“…However, numerous reports also indicate that production of antibiotics by Bacillus spp. can be affected by soil types (such as clay soil) (Campbell 1983;Campbell and Ephgrave 1983), organic matter (such as crop residues) (Weinhold and Bowman 1968), plant root exudates (such as carbohydrates and amino acids) (Bacilio-Jiménez et al 2003) and minerals (such as phosphate) (Milner et al 1995 and. Besides production of antibiotics, colonization of plant roots by microbial agents (Reva et al 2004), formation of biofilm on plant roots (Bais et al 2004), and competition for growth space and nutrients (Handelsman and Stabb 1996) are other important factors affecting efficacy of control of plant pathogens by Bacillus spp.…”

Ecological consequences of ingestion of Bacillus cereus on Bacillus thuringiensis infections and on the gut flora of a lepidopteran host

“…Zwittermicin concentrations accumulate and peak in sporulated cultures after 5 days of growth (Milner et al, 1995). K 2 PO 4 was omitted from the media because of its inhibition of zwittermicin A activity (Milner et al, 1995). Liquid cultures of B. cereus BGSC 6A4 and ATCC 11778 were filter sterilized (0.22 lm pore size, Millipore) to isolate secreted antibiotic, 500 ll of filtrate was added to the same volume of fresh broth plus 10 ll of a 30Â dilution of an 8 h culture of either a gut bacteria tester strain or a negative control.…”

“…Bacillus cereus were grown in modified tryptone-soya broth (TSB: tryptone 1.7%, soybean casein digest 0.3%, NaCl 0.5%, dextrose 0.25%, FeCl 3 0.5 mM) for 6 days at 28°C with continuous shaking in 6 ml of liquid media in a 30 ml Universal. Zwittermicin concentrations accumulate and peak in sporulated cultures after 5 days of growth (Milner et al, 1995). K 2 PO 4 was omitted from the media because of its inhibition of zwittermicin A activity (Milner et al, 1995).…”