Department of Pharmaceutical Chemistry, College of Pharmacy, Najran University, Najran 66462, Saudi Arabia.
School of Basic and Applied Sciences, Dayananda Sagar University, Bangalore 560111, India.
Molecules. 2022 Jun 29;27(13):4195. doi: 10.3390/molecules27134195.
Enzymes that degrade pectin are called pectinases. Pectinases of microbial origin are used in juice clarification as the process is cost-effective. This study screened a pectinase-producing bacterium isolated from soil and identified as 15A B-92 based on the 16S rRNA molecular technique. The purified pectinase from the isolate showed 99.6 U/mg specific activity and 11.6-fold purity. The molecular weight of the purified bacterial pectinase was 14.41 ± 1 kD. Optimum pectinase activity was found at pH 4.5 and 50 °C, and the enzyme was 100% stable for 3.5 h in these conditions. No enzymatic inhibition or activation effect was seen with Fe, Ca, or Mg. However, a slight inhibition was seen with Cu, Mn, and Zn. Tween 20 and 80 slightly inhibited the pectinase, whereas iodoacetic acid (IAA), ethylenediaminetetraacetate (EDTA), urea, and sodium dodecyl sulfate (SDS) showed potent inhibition. The bacterial pectinase degraded citrus pectin (100%); however, it was inactive in the presence of galactose. With citrus pectin as the substrate, the Km and Vmax were calculated as 1.72 mg/mL and 1609 U/g, respectively. The high affinity of pectinase for its substrate makes the process cost-effective when utilized in food industries. The obtained pectinase was able to clarify orange and apple juices, justifying its application in the food industry.
能够降解果胶的酶被称为果胶酶。微生物来源的果胶酶用于果汁澄清，因为该过程具有成本效益。本研究从土壤中筛选出一种产果胶酶的细菌，并根据 16S rRNA 分子技术将其鉴定为 15A B-92。从分离物中纯化的果胶酶表现出 99.6 U/mg 的比活性和 11.6 倍的纯度。纯化的细菌果胶酶的分子量为 14.41 ± 1 kD。最佳果胶酶活性在 pH 4.5 和 50°C 下发现，在这些条件下，酶在 3.5 小时内保持 100%稳定。Fe、Ca 或 Mg 对酶没有抑制或激活作用。然而，Cu、Mn 和 Zn 对酶有轻微的抑制作用。吐温 20 和 80 对果胶酶有轻微抑制作用，而碘乙酸（IAA）、乙二胺四乙酸（EDTA）、尿素和十二烷基硫酸钠（SDS）则表现出强烈的抑制作用。该细菌果胶酶能够降解柑橘果胶（100%）；然而，在存在半乳糖的情况下，它是无活性的。以柑橘果胶为底物时，Km 和 Vmax 分别计算为 1.72 mg/mL 和 1609 U/g。果胶酶对其底物的高亲和力使其在食品工业中具有成本效益。获得的果胶酶能够澄清橙汁和苹果汁，证明其在食品工业中的应用是合理的。
