Pectinolytic enzymes secreted by yeasts from tropical fruits

Abstract

Three hundred yeasts isolated from tropical fruits were screened in relation to secretion of pectinases. Twenty-one isolates were able to produce polygalacturonase and among them seven isolates could secrete pectin lyase. None of the isolates was able to secrete pectin methylesterase. The pectinolytic yeasts identified belonged to six different genera. Kluyveromyces wickerhamii isolated from the fruit mangaba (Hancornia speciosa) secreted the highest amount of polygalacturonase, followed by K. marxianus and Stephanoascus smithiae. The yeast Debaryomyces hansenii produced the greatest decrease in viscosity while only 3% of the glycosidic linkages were hydrolysed, indicating that the enzyme secreted was an endo-polygalacturonase. The hydrolysis of pectin by polygalacturonase secreted by S. smithiae suggested an exo-splitting mechanism. The other yeast species studied showed low polygalacturonase activity.

Isolation of a yeast strain able to produce a polygalacturonase with maceration activity of cassava roots

“…The Petri dishes were incubated at 30 °C for 3 days and then flooded with 5 N HCl. Pectinolytic activity was indicated by the formation of a clear halo around the colonies (SCHWAN; COOPER; WHEALS, 1997;DA SILVA et al, 2005).…”

“…As far as it is known; these enzymes could be involved in substrate colonization (fruits). This causes the breakdown of plant tissues with the concomitant release of sugars from plant cells, which in turn can be used for yeast growth, hence causing further spoilage (DA SILVA et al, 2005). It can be concluded that W. anomalus may belong to the second group of yeasts.…”

“…Yeasts have advantages compared to filamentous fungi with regards to the production of pectinases because they are unicellular, and their growth is relatively simple in economical culture media and relatively easier to perform at larger scale (DA SILVA et al, 2005).…”

Optimization of biomass, pellet size and polygalacturonase production by Aspergillus sojae ATCC 20235 using response surface methodology

“…It is well documented, that several organisms are able to produce pectin degrading enzymes including plants, filamentous fungi, bacteria and yeast [9][10][11][12]. For industrial purposes moulds such as Aspergillus niger, Coniotryrium diplodiela, Penicillum and Rhizopus species are preferred, because as much as 90% of the enzyme can be excreted into the culture medium [9,[13][14][15].…”

“…For industrial purposes moulds such as Aspergillus niger, Coniotryrium diplodiela, Penicillum and Rhizopus species are preferred, because as much as 90% of the enzyme can be excreted into the culture medium [9,[13][14][15]. Pectinase production by filamentous fungi varies according to the type of strain, cultivation conditions (pH, temperature, aeration, agitation and incubation time) and the growth medium composition (particularly carbon and nitrogen sources) [16].…”