scholarly journals Performance, yield and characteristics of bioflocculants (UPMBF13) produced by Bacillus subtilis UPMB13 during submerged and solid-state fermentation

2016 ◽  
Vol 18 (3) ◽  
pp. 611-620 ◽  

<div> <p>This study compares the distinctive performance, yield and characteristics of bioflocculants (UPMBF13) derived from submerged (SmF) and solid-state fermentation (SSF) of <em>Bacillus subtilis</em> UPMB13. The bioflocculants were subjected to morphological characterization, functional groups determination, molecular weight measurement, protein content quantification and specific compound identification. The SmF and the SSF strategies yielded an average of 2.70 g l<sup>-1</sup> and 1.25 g kg<sup>-1</sup> of UPMBF13, respectively. The submerged UPMBF13 resulted in a clear suspension with visible flocs formation, while flocs from the SSF treatment were less apparent. Higher total proteinaceous contents of UPMBF13 from the SSF led to the inferiority in flocculating performances. The produced UPMBF13 consisted of hydroxyl, carboxyl, methoxyl and carbonyl functional groups which contributed to their flocculating abilities. The molecular weights of UPMBF13 were around 10-50 kDa, characterizing them into low-molecular weight bioflocculants. The submerged UPMBF13 were more fibrous in nature than the SSF, giving the submerged UPMBF13 the upper hand in flocculation. SmF was the best fermentation method yielding high performing bioflocculants at a faster rate by the utilization of non-elaborative techniques. SSF, on the other hand, was proven feasible but further improvements are needed.&nbsp;</p> </div> <p>&nbsp;</p>

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hamid Mukhtar ◽  
Ikramul Haq

The present study describes the screening of different agroindustrial byproducts for enhanced production of alkaline protease by a wild and EMS induced mutant strain ofBacillus subtilisIH-72EMS8. During submerged fermentation, different agro-industrial byproducts were tested which include defatted seed meals of rape, guar, sunflower, gluten, cotton, soybean, and gram. In addition to these meals, rice bran, wheat bran, and wheat flour were also evaluated for protease production. Of all the byproducts tested, soybean meal at a concentration of 20 g/L gave maximum production of the enzyme, that is, 5.74  ±  0.26 U/mL from wild and 11.28  ±  0.45 U/mL from mutant strain, during submerged fermentation. Different mesh sizes (coarse, medium, and fine) of the soybean meal were also evaluated, and a finely ground soybean meal (fine mesh) was found to be the best. In addition to the defatted seed meals, their alkali extracts were also tested for the production of alkaline protease byBacillus subtilis, but these were proved nonsignificant for enhanced production of the enzyme. The production of the enzyme was also studied in solid state fermentation, and different agro-industrial byproducts were also evaluated for enzyme production. Wheat bran partially replaced with guar meal was found as the best substrate for maximum enzyme production under solid state fermentation conditions.


1982 ◽  
Vol 152 (1) ◽  
pp. 166-174
Author(s):  
J A Mulder ◽  
G Venema

A comparison of the nucleolytic activities in competent and physiologically low-competent wild-type cultures of Bacillus subtilis in DNA-containing sodium dodecyl sulfate-polyacrylamide gels revealed the existence of three competence-associated nuclease activities with apparent molecular weights of 13,000, 15,000, and 26,000. The three activities, which were dependent on manganese or magnesium ions, were specifically present in the competent fraction of a competent culture. The competence-associated nucleolytic activities of eight transformation-defective mutant strains were assayed, resulting in the following three classes of mutants: (i) four strains which, according to this assay, were not impaired in any of the nucleolytic activities mentioned above; (ii) one strain which was strongly impaired in the 13,000- and 26,000-molecular-weight activities, but showed a considerable level of the 15,000-molecular-weight activity; and (iii) three strains which were severely impaired in all three activities. The results indicated that the 26,000-molecular-weight activity was a dimer of the 13,000-molecular-weight activity and that this nuclease was involved in the entry of DNA.


Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 52 ◽  
Author(s):  
Yong Xing Tan ◽  
Wai Kit Mok ◽  
Jaslyn Lee ◽  
Jaejung Kim ◽  
Wei Ning Chen

Brewers’ spent grains (BSG) are underutilized food waste materials produced in large quantities from the brewing industry. In this study, solid state fermentation of BSG using Bacillus subtilis WX-17 was carried out to improve the nutritional value of BSG. Fermenting BSG with the strain WX-17, isolated from commercial natto, significantly enhanced the nutritional content in BSG compared to unfermented BSG, as determined by the marked difference in the level of metabolites. In total, 35 metabolites showed significant difference, which could be categorized into amino acids, fatty acids, carbohydrates, and tricarboxylic acid cycle intermediates. Pathway analysis revealed that glycolysis was upregulated, as indicated by the drop in the level of carbohydrate compounds. This shifted the metabolic flux particularly towards the amino acid pathway, leading to a 2-fold increase in the total amount of amino acid from 0.859 ± 0.05 to 1.894 ± 0.1 mg per g of BSG after fermentation. Also, the total amount of unsaturated fatty acid increased by 1.7 times and the total antioxidant quantity remarkably increased by 5.8 times after fermentation. This study demonstrates that novel fermentation processes can value-add food by-products, and valorized food waste could potentially be used for food-related applications. In addition, the study revealed the metabolic changes and mechanisms behind the microbial solid state fermentation of BSG.


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