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Direct bio-utilization of untreated rapeseed meal for effective iturin A production by Bacillus subtilis in submerged fermentation.

Jin H, Zhang X, Li K, Niu Y, Guo M, Hu C, Wan X, Gong Y, Huang F - PLoS ONE (2014)

Bottom Line: A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively.Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione.The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.

View Article: PubMed Central - PubMed

Affiliation: Oil Crops Research Institute, Chinese Academy of Agriculture Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China.

ABSTRACT
The feasibility of using untreated rapeseed meal as a nitrogen source for iturin A production by Bacillus subtilis 3-10 in submerged fermentation was first evaluated by comparison with two different commercial nitrogen sources of peptone and ammonium nitrate. A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively. It was shown that rapeseed meal had a positive induction effect on protease secretion, contributing to the release of soluble protein from low water solubility solid rapeseed meal for an effective supply of available nitrogen during fermentation. Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione. The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.

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Time courses of protease and cellulase concentrations with different nitrogen sources in bioreactor batch fermentation.•: rapeseed meal; ▪: peptone; ▴: ammonium nitrate. Error bars represent the standard deviation of the means (N = 3).
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pone-0111171-g004: Time courses of protease and cellulase concentrations with different nitrogen sources in bioreactor batch fermentation.•: rapeseed meal; ▪: peptone; ▴: ammonium nitrate. Error bars represent the standard deviation of the means (N = 3).

Mentions: The above results indicated more direct or efficient nitrogen assimilation from soluble peptone and ammonium nitrate resulted in faster growth of Bacillus subtilis compared to rapeseed meal (Figure 3A). Rapeseed meal provided an effective nitrogen source with low water solubility, so the release and utilization of rapeseed meal protein greatly depended on the degradation of proteases secreted by Bacillus subtilis. Moreover, both the cell growth and product iturin A synthesis relied on the continuous supply of available nitrogen from solid rapeseed meal. Therefore, protease activities from different nitrogen sources were compared during the fermentation. Figure 4A indicates that the secretion of protease was influenced greatly by the origin of nitrogen source, and there was an obvious induction effect of rapeseed meal on protease secretion. When rapeseed meal was used as a nitrogen source, protease increased with culture time, and the highest protease activity reached 2500 IU/mL at 70 h, which was 5 fold higher than that grown with peptone as the nitrogen source (Figure 4A). Interestingly, there was nearly no protease secretion when using ammonium nitrate as a nitrogen source.


Direct bio-utilization of untreated rapeseed meal for effective iturin A production by Bacillus subtilis in submerged fermentation.

Jin H, Zhang X, Li K, Niu Y, Guo M, Hu C, Wan X, Gong Y, Huang F - PLoS ONE (2014)

Time courses of protease and cellulase concentrations with different nitrogen sources in bioreactor batch fermentation.•: rapeseed meal; ▪: peptone; ▴: ammonium nitrate. Error bars represent the standard deviation of the means (N = 3).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215929&req=5

pone-0111171-g004: Time courses of protease and cellulase concentrations with different nitrogen sources in bioreactor batch fermentation.•: rapeseed meal; ▪: peptone; ▴: ammonium nitrate. Error bars represent the standard deviation of the means (N = 3).
Mentions: The above results indicated more direct or efficient nitrogen assimilation from soluble peptone and ammonium nitrate resulted in faster growth of Bacillus subtilis compared to rapeseed meal (Figure 3A). Rapeseed meal provided an effective nitrogen source with low water solubility, so the release and utilization of rapeseed meal protein greatly depended on the degradation of proteases secreted by Bacillus subtilis. Moreover, both the cell growth and product iturin A synthesis relied on the continuous supply of available nitrogen from solid rapeseed meal. Therefore, protease activities from different nitrogen sources were compared during the fermentation. Figure 4A indicates that the secretion of protease was influenced greatly by the origin of nitrogen source, and there was an obvious induction effect of rapeseed meal on protease secretion. When rapeseed meal was used as a nitrogen source, protease increased with culture time, and the highest protease activity reached 2500 IU/mL at 70 h, which was 5 fold higher than that grown with peptone as the nitrogen source (Figure 4A). Interestingly, there was nearly no protease secretion when using ammonium nitrate as a nitrogen source.

Bottom Line: A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively.Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione.The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.

View Article: PubMed Central - PubMed

Affiliation: Oil Crops Research Institute, Chinese Academy of Agriculture Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China.

ABSTRACT
The feasibility of using untreated rapeseed meal as a nitrogen source for iturin A production by Bacillus subtilis 3-10 in submerged fermentation was first evaluated by comparison with two different commercial nitrogen sources of peptone and ammonium nitrate. A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively. It was shown that rapeseed meal had a positive induction effect on protease secretion, contributing to the release of soluble protein from low water solubility solid rapeseed meal for an effective supply of available nitrogen during fermentation. Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione. The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.

Show MeSH