Falade Ayodeji O, Mabinya Leonard V, Okoh Anthony I, Nwodo Uchechukwu U
SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa.
Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa.
Biotechnol Appl Biochem. 2019 Jan;66(1):60-67. doi: 10.1002/bab.1696. Epub 2018 Nov 5.
The industrial applications and prospects of microbial peroxidase are on the upwards trend, thus necessitating the search for sources with high turnaround time. Actinobacterial species have been a major source of peroxidase for the obvious reasons of having robust metabolite expression capabilities. However, other bacteria species have been underexplored for peroxidase production, hence the motivation for the investigation into the peroxidase production potential of Raoultella ornithinolytica OKOH-1 (KX640917). The bacteria expressed optimum specific peroxidase activity of 16.48 ± 0.89 U mg , which is higher than those previously reported. The optimal fermentation conditions were pH 5 (3.44 ± 0.64 U mL ), incubation temperature of 35 °C (5.25 ± 0.00 U mL ), and agitation speed of 150 rpm (9.45 ± 2.57 U mL ), with guaiacol and ammonium chloride as the best inducer and nitrogen supplement, respectively. On valorization of agrowastes as a sole carbon source for the secretion of peroxidase, sawdust gave the best peroxidase yield (15.21 ± 2.48 U mg ) under solid-state fermentation. Also, a nonperoxide-dependent enzyme activity, which suggests probable laccase activity, was observed. The ability of the bacteria to utilize agrowastes is highly economical and as well a suitable waste management strategy. Consequently, R. ornithinolytica OKOH-1 is a promising industrial strain with dexterity for enhanced peroxidase production.
微生物过氧化物酶的工业应用和前景呈上升趋势，因此有必要寻找周转时间短的来源。放线菌物种一直是过氧化物酶的主要来源，原因显而易见，即具有强大的代谢物表达能力。然而，其他细菌物种在过氧化物酶生产方面的探索较少，因此有动力研究解鸟氨酸拉乌尔菌OKOH-1（KX640917）的过氧化物酶生产潜力。该细菌表达的最佳比过氧化物酶活性为16.48±0.89 U mg ，高于先前报道的值。最佳发酵条件为pH 5（3.44±0.64 U mL ）、培养温度35℃（5.25±0.00 U mL ）和搅拌速度150 rpm（9.45±2.57 U mL ），分别以愈创木酚和氯化铵作为最佳诱导剂和氮源补充剂。在用农业废弃物作为过氧化物酶分泌的唯一碳源进行增值时，锯末在固态发酵下的过氧化物酶产量最高（15.21±2.48 U mg ）。此外，还观察到一种非过氧化物依赖性酶活性，这表明可能存在漆酶活性。该细菌利用农业废弃物的能力具有很高的经济性，也是一种合适的废物管理策略。因此，解鸟氨酸拉乌尔菌OKOH-1是一种有前景的工业菌株，具有提高过氧化物酶产量的灵活性。
