Implication of Bacillus sp. in the production of pectinolytic enzymes during cocoa fermentation

Abstract

The role of bacilli in cocoa fermentation is not well known. Their potential of production of pectinolytic enzymes during this process was evaluated. Bacillus growth was monitored and pectinolytic strains were screened for their use of pectin as sole carbon source. Effects of cocoa fermentation parameters susceptible to influence on enzyme production were analysed. Among 98 strains isolated, 90 were positive for pectin degradation and 80% of them presented detectable pectinolytic activities in submerged fermentation. Forty-eight strains produced polygalacturonase (PG), 47 yielded pectin lyase (PL) and 23 strains produced both enzymes. Bacilli growth was not significantly affected during fermentation. PL production was favoured by galactose, lactose, glucose as sugars, and arginine, glutamine, cysteine and ammonium sulphate as nitrogen compounds. Pectin at low concentration (0.05%) and iron stimulated PL production. It was strongly repressed by galacturonic acid (1%), and negatively affected by nitrogen starvation, zinc and temperatures above 45°C. PL yield was very weak below pH 4.0 and in anaerobic conditions. PG production was weakened by sucrose and cation depletion. It was increased slightly by cysteine, ammonium nitrate and nitrogen starvation and significantly above 40°C. PG synthesis was not affected by acidic pH (3.0-6.0) or oxygen availability. As fermentation products, lactate and acetate lowered the production of both enzymes while ethanol had no effect. The high proportion of pectinolytic producers among the strains studied and analysis of factors influencing pectinolytic enzymes production, suggest that Bacillus sp. is liable to produce at least one enzyme during cocoa fermentation.

Performance, Immunity, Meat Composition and Fatty Acid Pattern in Broilers after Dietary Supplementation of Fermented Ginkgo biloba and Citrus junos

“…However, in the present study, although the weight was not significantly improved, the feed conversation efficiency was improved in the FCJP group compared to control. The pectin content of Citrus junos might be influenced by the probiotic organisms and activate to generate pectinolytic enzymes resulting in higher production of lactic acid bacteria [36,43,44]; where lactic acid bacteria can complement with the other beneficial microbes can exhibit synergism to utilize the feed with higher efficiency in broiler [45]. Therefore, combination of flavonoids, naringin, hesperidin, carotinoids, polyphenols, and flavonols, pectins, punicalagin, flavonoids, peduculagin, ellagitannin, and punicalin, some other phenolic compounds with the microbial generated organic compounds [34][35][36], the feed efficiency was improved in the FCJP2 group.…”

Chemical composition and physical quality characteristics of Ghanaian cocoa beans as affected by pulp pre-conditioning and fermentation

“…The considerably high shell content of all the unfermented samples could be ascribed to the adhering thick mucilaginous pulp immediately surrounding the testa prior to fermentation. Subsequent degradation of pectin by microbial pectinases during fermentation causes the liquefaction and drainage of about 10-50% of the pulp (Ouattara et al 2008) and this might have accounted for the relatively lower shell content in the fermented cocoa beans. Figure 1b also depicts a decrease in shell content as pod storage increased with beans stored for 21 days prior to fermentation having the lowest shell content (12.8%), and this could be attributed to the reduction in pulp volume by water evaporation occurring during pod storage .…”

Cocoa Fermentation from Agnéby-Tiassa: Biochemical Study of Microflora

“…Method described by [9] was used for the screening of yeast pectinolytic strains. Five wells of 0.5 cm in diameter and 2 to 3 mm in depth were made aseptically on plate agar containing a basal mineral medium (0.28% NH 4 SO 4 , 0.6% K 2 HPO 4 , 0.01% MgSO 4 , 0.2% KH 2 PO 4 , and 0.5% glucose) supplemented with 0.02% yeast extract, 1% pectin, and 1.7% agar adjusted pH to 5.6.…”

“…The method [9] described previously was used to evaluate the capacity of Bacillus strains to degrade pectin as sole carbon source.…”

“…The increased aeration, due to pectin degradation, promotes the development of acetic acid bacteria (AAB), which ferment the ethanol, a highly exothermic process [2,7,8]. Concerning Bacillus species; many reports have indicated presence of various species which grow throughout of fermentation process [3,9,10,11]. This microbial activity generates a range of metabolites end-products such as alcohols and organic acids which diffuse into beans to cause their death.…”