Department of Botany, Visva-Bharati, Santiniketan 731 235, West Bengal, India.
J Food Prot. 2009 Dec;72(12):2615-7. doi: 10.4315/0362-028x-72.12.2615.
Lactococcus lactis strain W8, which contains the nisin Z gene in its genome, grew well and produced nisin in cow's milk at temperatures of 30 to 37 degrees C. Maximum production of nisin was achieved at 6 h and was 4,000 activity units (AU) per ml in skim milk and 2,400 AU/ml in 3% fat milk. The organism produced nisin even in 20 times diluted skim milk and 3% fat milk at 1,000 and 600 AU/ml, respectively. Boiling of the fermented milk (pH 4.2) made with this culture allowed the separation of the liquid part (whey) from the curd. When 20 times diluted skim milk was fermented and the whey derived from it was lyophilized, the yield of nisin was 60,000 AU/g. The antimicrobial activity of the nisin preparation was stable for at least 1 year at refrigeration temperature. L. lactis W8 may have significant applications in the food industry for a cost-effective natural nisin preparation.
乳球菌（Lactococcus lactis）菌株 W8 的基因组中含有尼辛 Z 基因，在 30 至 37 摄氏度的牛奶中生长良好，并产生尼辛。在 6 小时时达到最大尼辛产量，脱脂奶中的产量为每毫升 4000 活性单位（AU），3%脂肪奶中的产量为 2400 AU/ml。该菌甚至在 1000 和 600 AU/ml 的 20 倍稀释脱脂奶和 3%脂肪奶中也能产生尼辛。用该培养物发酵的酸奶（pH4.2）在煮沸后可将液体部分（乳清）与凝乳分离。当发酵 20 倍稀释的脱脂奶并将从中获得的乳清冻干时，尼辛的产量为 60000 AU/g。尼辛制剂的抗菌活性在冷藏温度下至少稳定 1 年。L. lactis W8 可能在食品工业中有重要应用，因为它可以低成本制备天然尼辛。
