6 research outputs found
Laccase production by Coriolopsis caperata RCK2011: optimization under solid state fermentation by Taguchi DOE methodology
Laccase production by Coriolopsis caperata RCK2011 under solid state fermentation was optimized following Taguchi design of experiment. An orthogonal array layout of L(18) (2(1) Ă 3(7)) was constructed using Qualitek-4 software with eight most influensive factors on laccase production. At individual level pH contributed higher influence, whereas, corn steep liquor (CSL) accounted for more than 50% of the severity index with biotin and KH(2)PO(4) at the interactive level. The optimum conditions derived were; temperature 30°C, pH 5.0, wheat bran 5.0â
g, inoculum size 0.5â
ml (fungal cell mass = 0.015â
g dry wt.), biotin 0.5% w/v, KH(2)PO(4) 0.013% w/v, CSL 0.1% v/v and 0.5â
mM xylidine as an inducer. The validation experiments using optimized conditions confirmed an improvement in enzyme production by 58.01%. The laccase production to the level of 1623.55â
Ugds(â1) indicates that the fungus C. caperata RCK2011 has the commercial potential for laccase
Biological control of the grapevine diseases âgrey moldâ and âpowdery mildewâ by <i>Bacillus</i> <span style="mso-bidi-font-family:"Times New Roman"; mso-fareast-language:FR" lang="EN-US">B27 and B29 strains<span style="mso-bidi-font-style:italic"> </span></span>
109-115<span style="mso-ansi-language:EN-US;
mso-fareast-language:FR" lang="EN-US">Uncinula necator and Botrytis
cinerea are the most destructive pathogens
of the grapevine in Tunisia
and elsewhere.
We used <span style="mso-ansi-language:EN-US;mso-fareast-language:
FR" lang="EN-US">two strains of Bacillus subtilis group,
B27 and B29 to control powdery mildew and the grey mold disease of
the grapevine. Green house experiments showed that
B29 and B27 strains of the bacteria efficiently reduced the severity of powdery
mildew up to 50% and 60%, respectively. Further, they decreased Botrytis cinerea development
on grape leaf by 77% and 99%, respectively. The mode of action has been shown
to be chitinolytic. These two bacteria showed significant production of total
proteins discharged into the culture medium. Determination of some chitinolytic
enzymes revealed
the involvement of N-acetyl glucosaminidase (Nagase), the
chitin-1,4-chitobiosidase (Biase) and endochitinase in degrading the mycelium
of B. cinerea.
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