Jawan Roslina, Abbasiliasi Sahar, Tan Joo Shun, Mustafa Shuhaimi, Halim Murni, Ariff Arbakariya B
Bioprocessing and Biomanufacturing Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia.
Biotechnology Programme, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia.
Microorganisms. 2020 Sep 23;8(10):1454. doi: 10.3390/microorganisms8101454.
Antibacterial peptides or bacteriocins produced by many strains of lactic acid bacteria have been used as food preservatives for many years without any known adverse effects. Bacteriocin titres can be modified by altering the physiological and nutritional factors of the producing bacterium to improve the production in terms of yield and productivity. The effects of culture conditions (initial pH, inoculum age and inoculum size) and medium compositions (organic and inorganic nitrogen sources; carbon sources) were assessed for the production of bacteriocin-like inhibitory substances (BLIS) by Gh1 in shake flask cultures. An inoculum of the mid-exponential phase culture at 1% (/) was the optimal age and size, while initial pH of culture media at alkaline and acidic state did not show a significant impact on BLIS secretion. Organic nitrogen sources were more favourable for BLIS production compared to inorganic sources. Production of BLIS by Gh1 in soytone was 1.28-times higher as compared to that of organic nitrogen sources ((NH)2SO). The highest cell concentration (X = 0.69 ± 0.026 g·L) and specific growth rate (μ = 0.14 h) were also observed in cultivation using soytone. By replacing carbon sources with fructose, BLIS production was increased up to 34.94% compared to BHI medium, which gave the biomass cell concentration and specific growth rate of 0.66 ± 0.002 g·L and 0.11 h, respectively. It can be concluded that the fermentation factors have pronounced influences on the growth of Gh1 and BLIS production. Results from this study could be used for subsequent application in process design and optimisation for improving BLIS production by Gh1 at larger scale.
许多乳酸菌菌株产生的抗菌肽或细菌素作为食品防腐剂已使用多年，且无任何已知的不良影响。通过改变产细菌素细菌的生理和营养因素，可以调节细菌素的效价，从而在产量和生产率方面提高其产量。在摇瓶培养中，评估了培养条件（初始pH值、接种菌龄和接种量）和培养基组成（有机和无机氮源；碳源）对Gh1产生类细菌素抑制物质（BLIS）的影响。指数中期培养物1%（/）的接种物是最佳的菌龄和接种量，而培养基的初始pH值处于碱性和酸性状态时，对BLIS分泌没有显著影响。与无机氮源相比，有机氮源更有利于BLIS的产生。与有机氮源（(NH)2SO）相比，Gh1在大豆蛋白胨中产生的BLIS高出1.28倍。在使用大豆蛋白胨的培养中还观察到最高细胞浓度（X = 0.69 ± 0.026 g·L）和比生长速率（μ = 0.14 h）。用果糖替代碳源后，与脑心浸液培养基相比，BLIS产量提高了34.94%，脑心浸液培养基的生物量细胞浓度和比生长速率分别为0.66 ± 0.002 g·L和0.11 h。可以得出结论，发酵因素对Gh1的生长和BLIS的产生有显著影响。本研究结果可用于后续工艺设计和优化，以提高Gh1在更大规模上产生BLIS的应用。
