Abdelhamid Ahmed G, Campbell Emily P, Hawkins Zach, Yousef Ahmed E
Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States.
Botany and Microbiology Department, Faculty of Science, Benha University, Benha, Egypt.
Front Bioeng Biotechnol. 2022 May 13;10:869778. doi: 10.3389/fbioe.2022.869778. eCollection 2022.
Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial extraction and down-stream processing are highly desirable. Acid whey, a dairy industry waste, is explored as a medium for production of broad-spectrum antimicrobials from selected bacteriocinogenic bacteria. Neutralized and yeast extract-supplemented acid whey was suitable for production of antimicrobials by four tested strains, but OSY-EC was the most prolific antimicrobial producer. Concentrating synthesized antimicrobials during culture incubation using beads of polymeric adsorbent resin, followed by solvent extraction and freeze-drying, resulted in antimicrobials-rich powder (AMRP). Under these conditions, OSY-EC produced paenibacillin, polymyxin E, and fusaricidin, which are active against Gram-positive and Gram-negative bacteria and fungi, respectively. When media containing 2x and 4x minimum inhibitory concentrations of AMRP were inoculated with and , microbial populations decreased by ≥4-log CFU ml in tryptic soy broth and ≥3.5-log CFU ml in milk. The antimicrobial mechanism of action of AMRP solutions was attributed to the disruption of cytoplasmic membrane of indicator strains, and . These findings exemplify promising strategies for valorization of acid whey microbial bioreactions to yield potent antimicrobials.
细菌产生某些抗菌肽是一个资源密集型过程，因此，使用廉价的生长培养基并简化抗菌物质的提取和下游加工非常必要。酸乳清是乳制品工业的一种废料，被用作从选定的产细菌素细菌生产广谱抗菌剂的培养基。中和并添加酵母提取物的酸乳清适合四种受试菌株生产抗菌剂，但OSY-EC是最丰富的抗菌剂生产者。在培养过程中使用聚合吸附树脂珠浓缩合成的抗菌剂，然后进行溶剂萃取和冷冻干燥，得到富含抗菌剂的粉末（AMRP）。在这些条件下，OSY-EC产生了对革兰氏阳性菌、革兰氏阴性菌和真菌分别具有活性的芽孢杆菌素、多粘菌素E和镰孢菌素。当用 和 在含有2倍和4倍最小抑菌浓度AMRP的培养基中接种时，胰蛋白胨大豆肉汤中的微生物数量减少≥4个对数CFU/ml，牛奶中的微生物数量减少≥3.5个对数CFU/ml。AMRP溶液的抗菌作用机制归因于指示菌株 和 的细胞质膜的破坏。这些发现例证了酸乳清微生物生物反应以产生有效抗菌剂的有前景的策略。
