Stoichiometric equations are used to represent growth of microorganisms provided a ' molecular formula' for the cells is available. The molecular formula for biomass is obtained by measuring the amounts of C, N, H, O and other elements in cells. For a particular bacterial strain, the molecular formula was determined to be C4.4H7.30 1.2N0.86 . These bacteria are grown under aerobic conditions with hexadecane (C16H34) as substrate. The reaction equation describing growth is:

                             

You have been put in charge of a small fermenter for growing the bacteria and aim to produce 2.5 kg of cells for inoculation of a pilot-scale reactor. What minimum amount of hexadecane substrate must be contained in your culture medium? 

#Question id: 14273

#Section 5: Bioprocess Engineering and Process Biotechnology

Nicotiana tabacum cells are cultured to high density for production of polysaccharide gum. The reactor used is a stirred tank, containing initially 100 litres medium. The maximum specific growth rate of the culture is 0.18 d^-1 and the yield of biomass from substrate is 0.5 g g^-l. The concentration of growth-limiting substrate in the medium is 3% (w/v). The reactor is inoculated with 1.5 g l^{- 1} cells and operated in batch until the substrate is virtually exhausted; medium flow is then started at a rate of 4 l d^-1. Fed-batch operation occurs under quasi-steady-state conditions. Estimate the batch culture time.                                  ____________________

#Question id: 3863

#Section 3: Genetics, Cellular and Molecular Biology

Introns in nuclear pre-mRNAs are excised by:

#Question id: 15903

#Section 6: Plant, Animal and Microbial Biotechnology

#Question id: 14363

#Section 5: Bioprocess Engineering and Process Biotechnology

#Question id: 31210

#Section 7: Recombinant DNA technology and Other Tools in Biotechnology