Bioprocess Platform Design for Kefiran Production in Semi-Industrial Scale

Kefiran is a water soluble polysaccharide produced by the lactic acid bacteria Lactobacillus kefiranofaciens and composed of equal amount of glucose and galactose. This biopolymer has wide application in food and pharmaceutical industries based on its functional properties as antibacterial, antifungal, anti-inflammatory, immunomodulatory, and many other health benefits. In spite of many research were conducted for the wide applications of kefiran, little information is available on the industrial production of this important compound. However, the industrial production of kefiran is carried in submerged cultivation system using L. kefiranofaciens. The production of kefiran in industrial scale faces two main challenges. First, the low growth rate of the producer bacteria; second, the low yield of kefiran when cells cultivated in submerged culture. Thus, this study was focused at first on medium and bioprocess optimization of kefiran production in mono-culture system using different approaches. Furthermore, the production of polysaccahrides was significantly enhanced by using mixed culture composed of L. kefiranofaciens and Saccharomyces cerevisiae and medium optimization of this mixed culture cultivation system. Further improvement was then achieved when process scaled up to 16-L stirred tank bioreactor and the maximal kefiran production was achieved using fed-batch cultivation strategy under controlled pH and DO in level of 6.0 and 30% saturation, respectively. In the present work, complete industrial platform was designed for kefiran production in semi-industrial scale.