Effects of Selenium on the Growth and Fermentation Properties of Se-EnrichedBacillus Subtilis J-2

Abstract

This paper describes the effect of sodium selenite on the growth and fermentation properties of Bacillus subtilis J‐2 (BSJ‐2) which was isolated from the water of Chinese fermented pickles. The results of the optimum Se‐added conditions are as follows: addition concentration 45 μg/mL, addition time 4 h and inoculation quantity 2%. At this site, the Se conversion ratio was 73.8 ± 3.4%. With the increasing of selenium concentration, the alkaline protease activity has a slight increase at the optimum growth conditions, while the variation of the neutral protease activity had no significant difference among the five samples in the 1,000–1,100 μg/mL range. Added selenium had a positive impact on the antimicrobial ability of strains. Practical Applications The increasing popularity of Se‐enriched microorganism among food preservatives and food fermentation was well concerned about in the recent years. The present study has demonstrated that Bacillus subtilis has a suitable Se‐enriched condition and can enhance the growth and protease activities applied in food fermentation which can promote efficiency and cost savings. Health‐promoting effect is shown through the relatively high conversion on Se‐enriched Bacillus subtilis J‐2. It is expected that Se‐enriched B. subtilis J‐2 could be applied in food industries as an antiseptic agent to improve the antimicrobial ability. Our previous studies demonstrated that Se‐enriched B. subtilis can be applied as a safe and healthy potential dietary resource of nontoxic selenium to food fermentation and effective functional substance in food and medical industry.

Isolation of selenium‐resistant bacteria and advancement under enrichment conditions for selected probiotic Bacillus subtilis (BSN313)

“…However, the addition of Se after 4 hr showed the highest enrichment rate of 432.3 μg/g dw. A similar result was reported for Bacillus subtilis J‐2, in a study of Se enrichment optimization at 37°C with 45 μg/ml of Se, in Luria broth (Wu et al, 2016). Similarly, in our bioreactor fermentation, the Se addition times (0, 3, 9, and 12 hr) showed only a slight effect on the growth/cell density, at a concentration of 6 μg/ml of Se.…”

“…For microbial growth and Se enrichment, the Se addition time is important because, at different phases, the rate of growth varies and the additive may have dissimilar effects on the growth (Wu et al, 2016; Zhou et al, 2015). An Se addition time of 4–16 hr did not significantly affect the cell density (OD 600 ) for a 20 hr fermentation in a 250 ml SF.…”

Selenium Nanoparticle Synthesized by Proteus mirabilis YC801: An Efficacious Pathway for Selenite Biotransformation and Detoxification

“…Selenium (Se) is of considerable environmental importance, as it is an essential micronutrient with a prominent role in the health of various species [1,2]. For example, Se is required as a cofactor for numerous proteins, such as glutathione peroxidases and thioredoxin reductases in animals, and thus plays a pivotal role in removing the products of damage caused by free radicals and reactive oxygen species [3,4]. Moreover, selenium supplementation can significantly increase the activities of both selenium-dependent glutathione peroxidase (Se-GSH-Px) and superoxide dismutase [5,6].…”

Capacidad de bioconversión de selenio inorgánico por bacterias ácido lácticas desarrolladas en un medio enriquecido

“…Hasta estas concentraciones existen mecanismos de detoxificación, a través de una bioconversión de selenito a selenuro, probablemente por la acción de proteasas producidas para evitar el daño oxidativo a las células. La bioconversión del selenio inorgánico (Na 2 SeO 3 ) del medio es llevado a cabo mediante la unión de este elemento a un aminoácido, metionina o selenocisteína, o reemplazando al azufre de algunas proteínas (Wu et al, 2016).…”

“…7), la presencia del Además de sobrevivir, las bacterias son capaces de transformar el Se; así, se ha observado que la bioconversión de selenio llevada a cabo por microorganismos es más rápida y segura en comparación con los cereales crecidos en suelos enriquecidos con selenito de sodio. Las bacterias enriquecidas con selenio, tales como L. bulgaricus, en dosis de 1 a 16 mg/L, mejoran el valor nutritivo y la calidad del producto fermentado (Wu et al, 2015).…”