Statistical analysis of optimal culture conditions for Gluconacetobacter hansenii cellulose production

Abstract

Aim: The purpose of this study was to analyse the effects of different culture parameters on Gluconacetobacter hansenii (ATCC 10821) to determine which conditions provided optimum cellulose growth. Methods and Results: Five culture factors were investigated: carbon source, addition of ethanol, inoculation ratio, pH and temperature. jmp Software (SAS, Cary, NC, USA) was used to design this experiment using a fractional factorial design. After 22 days of static culture, the cellulose produced by the bacteria was harvested, purified and dried to compare the cellulose yields. The results were analysed by fitting the data to a first‐order model with two‐factor interactions. Conclusions: The study confirmed that carbon source, addition of ethanol, and temperature were significant factors in the production of cellulose of this G. hansenii strain. While pH alone does not significantly affect average cellulose production, cellulose yields are affected by pH interaction with the carbon source. Culturing the bacteria on glucose at pH 6·5 produces more cellulose than at pH 5·5, while using mannitol at pH 5·5 produces more cellulose than at pH 6·5. The bacteria produced the most cellulose when cultured on mannitol, at pH 5·5, without ethanol, at 20°C. Inoculation ratio was not found to be a significant factor or involved in any significant two‐factor interaction. Significance and Impact of the Study: These findings give insight into the conditions necessary to maximize cellulose production from this G. hansenii strain. In addition, this work demonstrates how the fractional factorial design can be used to test a large number of factors using an abbreviated set of experiments. Fitting a statistical model determined the significant factors as well as the significant two‐factor interactions.

The effect of pH, sucrose and ammonium sulphate concentrations on the production of bacterial cellulose (Nata-de-coco) by Acetobacter xylinum

“…In the present study the combination of low pH of 4.0 and sucrose concentration of 10% proved to produce good nata. Hutchens et al (2007) confirmed that carbon source, ethanol addition and temperature are significant factors in the production of cellulose by Gluconacetobacter hansenii. Further the same authors noted different sugars produced optimal cellulose yields at different pH values.…”

Statistical optimization of culture conditions for bacterial cellulose production by Acetobacter xylinum BPR 2001 from maple syrup

“…The productivity of BC depends on culture conditions, which include cultivation method, composition of growth medium (Keshk & Sameshima, 2005), dissolved oxygen (Kouda, Naritomi, Yano, & Yoshinaga, 1997), temperature, pH of the growth medium (Noro, Sugano, & Shoda, 2004), inoculation ratio (Hutchens, León, O'neill, & Evans, 2007) and inoculum age . The Plackett-Burman design and the response surface methodology (RSM) based on the Box-Behnken design can be used to optimize culture conditions (Plackett & Burman, 1946).…”

Process Parameters for Fermentation in a Rotary Disc Reactor for Optimum Microbial Cellulose Production using Response Surface Methodology

“…These include fruit juices (Kurosumi et al 2009), sugar cane molasses (Keshk and Sameshima 2006), sweet potato pulp (Shigematsu et al 2005), rotten apples (Gupta et al 2010), and maple syrup (Zeng et al 2011). The second factor is operating conditions such as dissolved oxygen (Kouda et al 1997), temperature, pH of the growth medium (Noro et al 2004), inoculation ratio (Hutchens et al 2007), and inoculum age. Both groups of factors must be at optimized levels to ensure optimum production of microbial cellulose.…”