Abstract

Sodium benzoate, the sodium salt of benzoic acid, is the first accepted and one of the widely used chemical preservatives in the food, cosmetic and, beverage industries. In recent past, soaring demand of packaged food resulted in increased industrialization and intensified use of chemical preservatives. The residual remains of these industries are discharged into their wastewater treatment plants (WWTP) and effluent treatment plants (ETP) thus concentrating the chemical preservatives in these treatment plants. This causes harmful effects on the growth of indigenous microbes in treatment plants and reduces the effectiveness of biological processes in secondary wastewater treatment. Therefore, it is necessary to degrade preservatives like sodium benzoate in the WWTP/ETP of industries. The ETP samples were collected from food processing industry for the isolation of sodium benzoate degrading aerobic bacteria. The microscopic analysis of the isolate with maximum ability to grow at a very high concentration of sodium benzoate (10 000 mg/L) showed it to be Gram-positive, endospore forming bacteria. The molecular characterization was done using 16S rDNA sequencing with universal primers and the isolate was identified as Bacillus subtilis DSSK1. The sequence was submitted to NCBI GenBank with accession number MT704505. The isolate was able to utilize sodium benzoate as the sole carbon and energy source. It was able to degrade 76% of sodium benzoate (10 000 mg/L) in 72 h. It was also able to produce hydrolytic and oxidative enzymes (cellulase, amylase, pectinase and laccase) which can help it to better survive in the food industry effluent rich in cellulose, starch, pectin, and lignin thus making it a promising candidate for industrial effluent treatment rich in benzoate.

中文翻译：

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食品工业废水中苯甲酸降解菌的分离鉴定

摘要

苯甲酸钠是苯甲酸的钠盐，是食品、化妆品和饮料行业中最早被接受和广泛使用的化学防腐剂之一。近来，对包装食品的需求飙升导致工业化程度提高和化学防腐剂的使用强度增加。这些工业的残余物被排放到它们的废水处理厂（WWTP）和污水处理厂（ETP），从而在这些处理厂中浓缩化学防腐剂。这会对处理厂中本地微生物的生长造成有害影响，并降低二级废水处理中生物过程的有效性。因此，有必要对工业污水处理厂/ETP中的苯甲酸钠等防腐剂进行降解。ETP样品取自食品加工业，用于苯甲酸钠降解需氧菌的分离。在非常高浓度的苯甲酸钠（10 000 mg/L）下具有最大生长能力的分离物的显微镜分析表明它是革兰氏阳性、内生孢子形成细菌。使用通用引物的 16S rDNA 测序进行分子表征，分离物被鉴定为枯草芽孢杆菌DSSK1。该序列以登录号 MT704505 提交给 NCBI GenBank。该分离物能够利用苯甲酸钠作为唯一的碳源和能源。它能够在 72 小时内降解 76% 的苯甲酸钠（10 000 mg/L）。它还能够生产水解和氧化酶（纤维素酶、淀粉酶、果胶酶和漆酶），这可以帮助它更好地在富含纤维素、淀粉、果胶和木质素的食品工业废水中生存，从而使其成为工业废水的有希望的候选者治疗富含苯甲酸盐。