Guava Psidium guajava seed flour and dry Aspergillus niger mycelium as nitrogen sources for the production of biomass and antimicrobial compounds produced by Weissella confusa

Abstract

Background:The fermentation substrate efficiency of glucose supplemented with guava seed flour (GGSF) or glucose supplemented with dry Aspergillus niger mycelium (GANM) was evaluated during the production of biomass and antimicrobial compounds by the lactic acid bacteria Weissella confusa. Results: The fermentation substrate efficiency was measured by comparing the biomass formation, substrate consumption, substrate conversion, antimicrobial activity and product yield. The antimicrobial activity was measured against a commercial Staphylococcus aureus strain. The results were compared against fermentations performed in a commercial substrate (CS), the MRS (Man-Rogosa-Sharpe) substrate. The fermentations were performed discontinuously for 4 hrs at 100 rpm and 32ºC. The biomass production exhibited a statistically significant difference (P ≤ 0.05) between treatments. The biomass production was 13.98% higher in the CS than in the GGSF and GANM substrates; however, there were no statistically significant differences for the specific growth rate. Conclusions: The GGSF and GANM substrates favored an antimicrobial activity against Staphylococcus aureus during the second and third hours of fermentation (inhibition diameter was 6.11% and 4.72%, respectively). The GGSF, GANM and CS substrates did not present statistically significant differences for the production of antimicrobial substances against Staphylococcus aureus. Therefore, GGSF and GANM can be considered as viable and economical alternative nitrogen sources for the production of the antimicrobial compounds formed by Weissella confusa in submerged fermentations.

Improving nitrogen source utilization from defatted soybean meal for nisin production by enhancing proteolytic function of Lactococcus lactis F44

“…In most cases, these nitrogen sources must be incorporated as a formulation, which dramatically increased the costs of large-scale nisin production 10 , 11 . Therefore, many studies have focused on searching for possible alternatives such as fishery residues 12 , 13 , muscle processing wastes 14 and agricultural wastes 15 – 17 to reduce the cost of L . lactis fermentation and nisin production.…”

Utilization of Fruit Seed-Based Bioactive Compounds for Formulating the Nutraceuticals and Functional Food: A Review

“…Serna-cock et al investigated the use of guava seed flour as a nitrogen source in alcoholic fermentation, finding that it increased product output and substrate conversion. These findings suggest that guava seed flour could be used as a low-cost, long-term supply of nitrogen for alcoholic fermentation ( 114 ). Several studies looked into using guava seed and pomace powder in cupcakes.…”

Caracterización del epicarpio de guayaba (Psidium guajava L.) como alternativa natural para uso en productos alimenticios procesados

“…La agroindustrialización de la guayaba presupone el descarte de sus subproductos (25-30% de la fruta), lo cual conduce a los problemas ambientales anteriormente anotados. Estos residuos (epicarpio y semillas) han sido aprovechados para la elaboración de compuestos antimicrobianos, producción de etanol, biomasa ácido-láctica y ácido láctico [11,12]. Sin embargo, el epicarpio de algunas frutas presenta gran importancia a nivel agroindustrial ya que contiene pigmentos carotenoides que pueden ser utilizados como fuente importante de colorantes naturales o de provitamina A [13,14].…”