title: Flocculation of dimorphic yeast Benjaminiella poitrasii is altered by modulation of NAD-glutamate dehydrogenase.
abstract: A strategy to control flocculation is investigated using dimorphic yeast, Benjaminiella poitrasii as a model. Parent form of this yeast (Y) exhibited faster flocculation (11.1 min) than the monomorphic yeast form mutant Y-5 (12.6 min). Atomic force microscopy revealed higher surface roughness of Y (439.34 rms) than Y-5 (52 rms). Also, the former had a zeta potential of -65.97+/-3.45 as against -50.21+/-2.49 for the latter. Flocculation of both Y and Y-5 could be altered by supplementing either substrates or inhibitor of NAD-glutamate dehydrogenase (NAD-GDH) in the growth media. The rate of flocculation was promoted by alpha-ketoglutarate or isophthalic acid and decelerated by glutamate with a statistically significant inverse correlation to corresponding NAD-GDH levels. These interesting findings open up new possibilities of using NAD-GDH modulating agents to control flocculation in fermentations for easier downstream processing.
authors.affiliation: Biochemical Sciences Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
authors.forename: C V
authors.initials: CV
authors.lastname: Joshi
authors.forename: V
authors.initials: V
authors.lastname: Ghormade
authors.forename: P
authors.initials: P
authors.lastname: Kunde
authors.forename: P
authors.initials: P
authors.lastname: Kulkarni
authors.forename: H
authors.initials: H
authors.lastname: Mamgain
authors.forename: S
authors.initials: S
authors.lastname: Bhat
authors.forename: K M
authors.initials: KM
authors.lastname: Paknikar
authors.forename: M V
authors.initials: MV
authors.lastname: Deshpande
mesh_terms: D003470:Culture Media; D005427:Flocculation; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D008954:Models, Biological; D009090:Mucorales / Q000201:enzymology* / Q000254:growth & development; D009243:NAD / Q000378:metabolism*
chemical_list: D003470:Culture Media; D009243:NAD; D005969:Glutamate Dehydrogenase