摘要
该研究以泡菜为原料,以金黄色葡萄球菌(Staphylococcus aureus)与大肠杆菌(Escherichia coli)为指示菌,通过溶钙圈法及牛津杯法初筛,苯乳酸产量检测复筛,从泡菜中分离筛选具有抑菌性能的高产苯乳酸菌株,将其应用于发酵豆粕以评估其产苯乳酸性能,并对其进行形态学观察、生理生化实验及分子生物学鉴定.结果表明,共获得8株具有抑菌效果的菌株,其中,菌株R69苯乳酸产量最高,为1.25 mg/mL,添加苯丙酮酸时,该菌株固态发酵豆粕的苯乳酸产量为425.70 mg/kg,该菌株被鉴定为植物乳杆菌(Lactobacillus plantarum).菌株R69固态发酵豆粕时,添加0.2％蛋白酶、3％糖蜜和0.15％苯丙酮酸可提高苯乳酸含量,苯乳酸含量达到624.49 mg/kg,且可有效抑制大肠杆菌和霉菌的生长.
Abstract
Using kimchi as raw material,Staphylococcus aureus and Escherichia coli as indicator bacteria,strains with antibacterial effect and high yield of phenyllactic acid were isolated from sauerkraut and primary screened by the calcium dissolution ring method and Oxford cup method and secondary screened by determing phenyllactic acid yield.The strains were applied to fermented soybean meal to evaluate their phenyllactic acid pro-duction performance,and the strains were identified by morphological observation,physiological and biochemical experiments and molecular biolog-ical identification.The results showed that a total of 8 strains with antibacterial effect were obtained,among which the strain R69 had the highest yield of phenyllactic acid(1.25 mg/ml).When phenylpyruvate acid was added,the yield of phenyllactic acid of solid fermented soybean meal was 425.70 mg/kg.The strain R69 was identified as Lactobacillus plantarum.The yield of phenyllactic acid could reach 624.49 mg/kg by using strain R69 for solid fermentation of soybean meal,with protease addition 0.2％,molasses 3％and phenylpyruvate 0.15％,and the growth of E.coli and mold was inhibited effectively.
维普
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