Screening of Yeast Strains for Pectinolytic Activity: Effects of Different Carbon and Nitrogen Sources in Submerged Fermentations

Abstract

Twenty yeast strains were screened for pectinolytic activity, among the strains, only nine were positive for pectinase production. The best strain was Kluyveromyces marxianus NRRL-Y-1109 which gave high quantities of pectinase activity, by submerged fermentation. Different parameters such as incubation time, pH (3.5-7), temperature (20-45°C), nitrogen and carbon source, were optimized. The optimal incubation time, temperature and pH for pectinase production were found to be 48 h, 30°C and 6, respectively. Studies were conducted on the production of pectinase in submerged fermentation using agro-industrial residues such as wheat bran, grape waste, brewer's malt, beet molasses and corncob at a concentration of 1.5% (wt./vol.). Under optimized fermentation conditions, maximal enzyme were produced when citrus pectin (4.8 U/mL) was used as the carbon source, but high enzyme production was also obtained on wheat bran (2.2 U/mL) and grape waste (1.8 U/mL) in shaking conditions (120 rpm) for 48 h. Peptone and yeast extract used together as nitrogen source gave best enzyme production. The effects of temperature (30-70°C), pH (3.5-8) and salt concentration (1, 2, 5 and 10%) on the pectinase activity were determined. The optimum activity was obtained when temperature 45°C and pH at 5.5. The enzyme was stable at 45°C for more than 50 min, suggesting that it is relatively thermostable and being of interests for food processing.

Biocontrol ability and action mechanisms of Aureobasidium pullulans GE17 and Meyerozyma guilliermondii KL3 against Penicillium digitatum DSM2750 and Penicillium expansum DSM62841 causing postharvest diseases

“…Pectinase enzyme led to softening of fruits tissue as a result of destruction of pectin molecules, which are high molecular weight acid polysaccharides present in plant cell walls primarily made up of α‐(1 → 4) linked D‐galacturonic acid residues (Oskay & Yalçin, 2015). The lack of pectinase activity in the yeasts A. pullulans GE17 and M. guilliermondii KL3 used in this study was considered as an advantage, because this characteristic could help to maintain fruit firmness and prevent softening when these yeasts are applied to the surfaces of fruits for biocontrol purposes.…”

“…Ability of selected yeasts to produce and secrete five different cell wall lytic enzymes, chitinase (Souza et al, 2009), pectinase (Oskay & Yalçin, 2015), β‐1,3 glucanase (Lutz, Lopes, Rodriguez, Sosa, & Sangorrin, 2013), protease (Gullino) and gelatinase (Pickett, Greenwood, & Harvey, 1991) were characterized. The presence of chitinase was determined on solid medium containing colloidal chitin (Sigma C7170, USA), pectinase activity was tested on citruspectin (Sigma P9135, Denmark), β‐1,3 glucanase activity on laminarin (Sigma L9634, USA), protease activity on skim milk powder (Sigma‐Aldrich 70166, Switzerland), whereas gelatinase activity was checked on sterilized tubes including gelatin as a substrate.…”

“…Ability of selected yeasts to produce and secrete five different cell wall lytic enzymes, chitinase (Souza et al, 2009), pectinase (Oskay & Yalçin, 2015), β-1,3 glucanase (Lutz, Lopes, Rodriguez, Sosa, & Sangorrin, 2013), protease (Gullino) and gelatinase (Pickett, Greenwood, & Harvey, 1991)…”

“…Pectinase enzyme led to softening of fruits tissue as a result of destruction of pectin molecules, which are high molecular weight acid polysaccharides present in plant cell walls primarily made up of α-(1 ! 4) linked D-galacturonic acid residues (Oskay & Yalçin, 2015).…”

Enhancement of novel Endo-polygalacturonase expression in Rhodotorula mucilaginosa PY18: insights from mutagenesis and molecular docking

“…However, the production of pectinase in yeasts is not as common as in other microorganisms. Rhodotorula glutinis MP-10, isolated from tannin-rich persimmon fruits, has been reported to co-produce tannase and pectinase by both free and immobilized cells [ 7 ]. This highlights the potential of yeasts to produce pectinolytic enzymes, despite their limited occurrence in this group of microorganisms [ 1 ].…”