A bacterial culture having a specific oxygen uptake rate of 5 mmol O2 (g- DCW)^-1h-1 is being grown aerobically in a fed-batch reactor. The maximum value of the volumetric oxygen transfer coefficient is 0.18 s for the stirred tank bioreactor and the critical dissolved oxygen concentration is 20% of the saturation concentration (8 mg L^-1). The maximum density to which the cells can be grown in the fed-batch process, without the growth being limited by oxygen transfer, is approximately

#Question id: 10791

#Section 6: Plant, Animal and Microbial Biotechnology

Following are certain statements regarding furanocoumarins;

 a) furanocoumarins have an attached furan ring

 b) These compounds are toxic until they are activated by sunlight in the ultraviolet A (UV-A) region (320–400 nm)  

 c) Light activated furanocoumarins can insert themselves into the double helix of DNA and bind to the pyrimidine bases, thus blocking transcription and repair and leading eventually to cell death   

 d) Phototoxic furanocoumarins are especially abundant in members of the Umbelliferae family, including celery, parsnip, and parsley.

 Which of the following combination from the above statements is correct?

#Question id: 10792

#Section 6: Plant, Animal and Microbial Biotechnology

Compounds such as caffeic acid and ferulic acid occur in soil in appreciable amounts and have been shown,

#Question id: 10793

#Section 6: Plant, Animal and Microbial Biotechnology

Hydroxyl groups (−OH),  and methoxy groups(−OCH3) modification provides colour variations in case of

#Question id: 10794

#Section 6: Plant, Animal and Microbial Biotechnology

Which one of the following characteristics of about lignin is incorrect?

#Question id: 10795

#Section 6: Plant, Animal and Microbial Biotechnology

basic carbon skeleton of a flavonoid contains 15 carbons arranged in two aromatic rings connected by a three-carbon bridge. This structure results from two separate biosynthetic pathways:

#Question id: 10796

#Section 6: Plant, Animal and Microbial Biotechnology

Flavonoids are one of the largest classes of plant phenolics, structure of flavonoids;