Starter culture were prepared by inoculating the selected strain in 100 ml GM medium and incubated on a shaker (150 rpm) at 37ºC for 48 hrs. The starter culture containing 1.5x104 viable cells/ml was inoculated (10%) to GM medium supplemented with various nutrients compositions by varying carbon sources & concentrations (glucose, fructose or acetate at 0-6 g/l), nitrogen sources & concentrations ((NH4)2SO4, NH4NO3 & NH4Cl at 0-0.2 g/l), mineral salts (KH2PO4, K2HPO4, MgSO4, CaCl2 & MnSO4 at 0-1 g/l) and vitamin (nicotinic acid, r-aminobenzoic acid, thiamine each at 0-1 mg/l, biotin at 0-0.01 mg/l or no addition of vitamin). The cells were cultivated on a shaker (150 rpm) at 37ºC under aerobic-dark condition. Growth (in term of dried cell weight, DCW), pH and PHB content were determined at the end of cultivation (60 hrs).

Fermentation is the term used to describe any process for the production of a product by means of the culture of microorganisms or cells. Fermentation is often thought of as the first step in many biotechnology processes. Organic biological molecules, microbes, therapeutics, enzymes, antibiotics and vaccines are all produced using fermentation. Fermentation covers a wide range of subjects from the biological point of view, such as care & maintenance of bacterial strains, conditions affecting the growth of bacteria, modelling of bacterial growth pattern. It also tackles the hardware angle, including the design & construction of a fermenter & the use of probes to measure the state of a culture. Although the main emphasis is on organisms, McNeil and Harvey also describe fermentation in animal cells - a nice touch. Contract fermentation & cell culture services offers custom fermentation services for the production of microbial cells & their products in volumes up to 375 liters under BSL2 containment. Tissue culture facilities are also available for the production of various animal cells, such as HeLa S3's and 293 cells for adenovirus propogation.

Lignocellulosic materials represent a large and inexpensive resource because they cannot be digested and therefore do not compete as food. However, their inability do be digested makes them difficult to convert to fermentable sugars. Indeed, the fermentation of sugars derived from lignocellulosic matter has proven to be more of a process design and operating challenge than traditional sugar or starch-based processes. The bioconversion of lignocellulosic biomass to ethanol is a complicated series of strongly interdependent process steps. In the enzymatic hydrolysis of cellulose to obtain water-soluble sugars, the enzyme source is the aqueous culture mass obtained in an enzyme preparation step by cultivating an aqueous nutrient medium in the presence of a cellulosic material. A cellulolytic microorganism is capable of elaborating a cellulolytic enzyme complex which can degrade native cellulose. No separation is made of any component of the culture mass. Such use of the culture mass as the enzyme source not only eliminates processing steps to separate the enzyme, but also results in increased hydrolysis rates and yields of the desired water-soluble sugars in the hydrolysis of cellulose