Falade Ayodeji O, Mabinya Leonard V, Okoh Anthony I, Nwodo Uchechukwu U
SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, 5700, Eastern Cape, South Africa.
Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice, 5700, Eastern Cape, South Africa.
Heliyon. 2019 Dec 12;5(12):e03012. doi: 10.1016/j.heliyon.2019.e03012. eCollection 2019 Dec.
This study sought to determine the process conditions for optimum peroxidase production by a species ( sp. FALADE-1-KX640922) isolated from Hogsback forest reserve in South Africa and characterize the peroxidase gene in the bacteria. We optimized peroxidase production by manipulating the environmental and nutritional parameters under submerged fermentation. Subsequently, the gene encoding heme-peroxidase was determined through nested polymerase chain reaction and Sanger DNA sequencing. The studied bacteria had maximum peroxidase production at pH 8, 30 °C and 150 rpm. The addition of guaiacol to lignin fermentation medium enhanced peroxidase production by over 100 % in the studied bacteria. However, the other lignin monomers (veratryl alcohol, vanillin, vanillic acid and ferulic acid) repressed the enzyme activity. Modification of the fermentation medium with ammonium sulphate gave the maximum peroxidase yield (8.87 U mL). Under the predetermined culture conditions, sp. FALADE-1 expressed maximum specific peroxidase activity at 48 h (8.32 U mg). Interestingly, a search of the sequenced gene in PeroxiBase showed 100% similarity to catalase-peroxidase gene (), as well, the deduced protein sequence clustered with bacterial catalase-peroxidases and had a molecular weight of about 11.45 kDa with 7.01 as the estimated isoelectric point. Subsequently, the nucleotide sequence was deposited in the National Center for Biotechnology Information (NCBI) repository with the accession number MF407314. In conclusion, sp. FALADE-1 is a promising candidate for improved peroxidase production.
本研究旨在确定从南非霍克斯贝格森林保护区分离出的一个物种（FALADE-1-KX640922菌株）产生最佳过氧化物酶的工艺条件，并对该细菌中的过氧化物酶基因进行表征。我们通过在深层发酵过程中控制环境和营养参数来优化过氧化物酶的产生。随后，通过巢式聚合酶链反应和桑格DNA测序确定了编码血红素过氧化物酶的基因。所研究的细菌在pH 8、30°C和150 rpm条件下过氧化物酶产量最高。在木质素发酵培养基中添加愈创木酚可使所研究细菌的过氧化物酶产量提高100%以上。然而，其他木质素单体（藜芦醇、香草醛、香草酸和阿魏酸）会抑制酶活性。用硫酸铵改良发酵培养基可获得最高的过氧化物酶产量（8.87 U/mL）。在预定的培养条件下，FALADE-1菌株在48小时时表达出最高的比过氧化物酶活性（8.32 U/mg）。有趣的是，在PeroxiBase中对测序基因的搜索显示，其与过氧化氢酶-过氧化物酶基因（）有100%的相似性，此外，推导的蛋白质序列与细菌过氧化氢酶-过氧化物酶聚类，分子量约为11.45 kDa，估计的等电点为7.01。随后，该核苷酸序列被存入美国国立生物技术信息中心（NCBI）数据库，登录号为MF407314。总之，FALADE-1菌株是提高过氧化物酶产量的一个有前景的候选菌株。
