None of the authors of this manuscript has any financial or personal relationship with other people or organizations that could inappropriately influence their work.to their wide range of biotechnological applications, such as shellfish waste management (Nakagawa et al., 2011), generation of fungal protoplasts (Fleuri et al., 2009), production of single cell protein (Wang et al., 2006), production of N-acetyl-b-D-glucosamine (GlcNAc) and derivatives (Lin et al., 2009) and bio-control of fungal plant pathogens (Joo, 2005).Despite the potential commercial benefits, the application of chitinases has been limited by low productivity (Liu et al., 2013), which is of particular relevance to the production by the enzymatic degradation of chitin. Thus, increasing the levels of chitinase production is a key to improving GlcNAc production on an industrial scale. In a previous study, increasing the chitinase production , mainly via strain screening (Meena et al., 2013), strain mutation (Li et al., 2007), genetic modification (Iqbal et al., 2012) and medium optimization (Singh et al., 2013). Furthermore, the control of culture conditions, including the pH, was shown to be important for controlling the level of chitinase activity.The effect of pH on cell growth and enzyme production differs among microorganisms. Chitinase can be divided into alkaline (Bhushan and Hoondal, 1998), acidic (Chang et al., 2014), and neutral (Takeo et al., 2009) chitinase, according to its isoelectric point. The change of the growth medium pH owing to the accumulation of GlcNAc produced by the hydrolysis of chitin (Halder et al., 2013) does not benefit both cell growth and chitinase production in chitinase fermentation. However, there are few reports about the effect of pH on chitinase production in batch fermentation.A highly efficient chitinolytic bacterium Chitinolyticbacter meiyuanensis SYBC-H1 producing alkaline chitinase was isolated in our lab (Hao et al., 2011a, b;Zhang et al., 2016). In the present study, the influence Enhanced chitinase production by Chitinolyticbacter meiyuanensis SYBC-H1 using staged pH control (Received August 22, 2015 The pH of a microbiological culture is important for both cell growth and chitinase accumulation, but the optimal pH is not normally the same for both. The objective of this study was to investigate the effect of pH on chitinase production by Chitinolyticbacter meiyuanensis strain SYBC-H1 (ATCC BAA-2140) in a mineral medium. The results of batch culture at different pH values showed that the optimum pH for cell growth and chitinase production varied with time, although KOH produced the best results for cell growth and chitinase production, NaOH was chosen because of cost considerations. We designed a three-stage pH control strategy using NaOH as the neutralizing agent. Maximum cell growth (1.07 g dry cell weight/l) and maximum chitinase activity (13.6 U/ml) were observed after culture at 26∞C for 72 h in a mineral medium. These values were greater by 129% and 162%, respectively, and the length of time...