An Alkalothermophilic Amylopullulanase from the Yeast Clavispora lusitaniae ABS7: Purification, Characterization and Potential Application in Laundry Detergent

In the present study, α-amylase and pullulanase from Clavispora lusitaniae ABS7 isolated from wheat seeds were studied. The gel filtration and ion-exchange chromatography revealed the presence of α-amylase and pullulanase activities in the same fraction with yields of 23.88% and 21.11%, respectively. SDS-PAGE showed a single band (75 kDa), which had both α-amylase (independent of Ca2+) and pullulanase (a calcium metalloenzyme) activities. The products of the enzymatic reaction on pullulan were glucose, maltose, and maltotriose, whereas the conversion of starch produced glucose and maltose. The α-amylase and pullulanase had pH optima at 9 and temperature optima at 75 and 80 °C, respectively. After heat treatment at 100 °C for 180 min, the pullulanase retained 42% of its initial activity, while α-amylase maintained only 38.6%. The cations Zn2+, Cu2+, Na+, and Mn2+ increased the α-amylase activity. Other cations Hg2+, Mg2+, and Ca2+ were stimulators of pullulanase. Urea and Tween 80 inhibited both enzymes, whereas EDTA only inhibited pullulanase. In addition, the amylopullulanase retained its activity in the presence of various commercial laundry detergents. The performance of the alcalothermostable enzyme of Clavispora lusitaniae ABS7 qualified it for the industrial use, particularly in detergents, since it had demonstrated an excellent stability and compatibility with the commercial laundry detergents.

Microbial conversion of optically active (R) 3 Chloro-1,2-propandiol by Clavispora lusitaniae MGR5 KY209902

The MCH assimilation Clavispora lusitaniae MGR5 (KY209902) was isolated from sugarcane juice using a screening medium. The preliminary assimilation was exercised with Clavispora lusitaniae MGR5 grown on synthetic medium and assimilation by pH change of the medium was observed. The specific rotation of R-3- Chloro-1,2-propanediol was -6 (c=2.5, in C2H5OH) in conditions with enatiomeric excess of 92.8 % Clavispora lusitaniae MGR5 product. The sharp peaks in HPLC spectrum of R 3 Chloro-1,2-propanediol in the retention time peak was of 2.38 min and concentration 100%. The structural and dynamic properties of R-3-Chloro-1,2-propanediol in GCMS spectrum were obtained. The IR spectrum, a shallow broad band at wavelength 3309.8 signifies the presence of O-H stretching, the narrow peak at 1087.85 indicates the presence of C=O stretching in conjugation with functional group of R- 3 Chloro-1,2-propanediol(C3H7ClO2). These results concluded that the strain assimilated with stereo inversion of R-3- Chloro-1,2-propanediol via RS 3- chloro-1,2-propanediol. The possibility to produce optically active R-3- Chloro-1,2-propanediol was discussed.

Yeast Microbiota during Sauerkraut Fermentation and Its Characteristics

Sauerkraut is the most important fermented vegetable obtained in Europe. It is produced traditionally by spontaneous fermentation of cabbage. The aim of this study was to determine biodiversity of yeasts present during fermentation of eight varieties of cabbages (Ambrosia, Avak, Cabton, Galaxy, Jaguar, Kamienna Głowa, Manama and Ramco), as well as characterize obtained yeast isolates. WL Nutrient Agar with Chloramphenicol was used to enumerate yeast. Isolates were differentiated using RAPD-PCR and identified by sequencing of the 5.8S-ITS rRNA gene region. The volatiles production was analyzed using SPME-GC-TOFMS. Our research confirmed that during sauerkraut fermentation there is an active growth of the yeasts, which begins in the first phases. The maximal number of yeast cells from 1.82 to 4.46 log CFU g−1 occurred after 24 h of fermentation, then decrease in yeast counts was found in all samples. Among the isolates dominated the cultures Debaryomyces hansenii, Clavispora lusitaniae and Rhodotorula mucilaginosa. All isolates could grow at NaCl concentrations higher than 5%, were relatively resistant to low pH and the presence of lactic acid, and most of them were characterized by killer toxins activity. The highest concentration of volatiles (mainly esters and alcohols) were produced by Pichia fermentans and D. hansenii strains.

Protection of Citrus Fruits from Postharvest Infection with Penicillium digitatum and Degradation of Patulin by Biocontrol Yeast Clavispora lusitaniae 146

Fungal rots are one of the main causes of large economic losses and deterioration in the quality and nutrient composition of fruits during the postharvest stage. The yeast Clavispora lusitaniae 146 has previously been shown to efficiently protect lemons from green mold caused by Penicillium digitatum. In this work, the effect of yeast concentration and exposure time on biocontrol efficiency was assessed; the protection of various citrus fruits against P. digitatum by C. lusitaniae 146 was evaluated; the ability of strain 146 to degrade mycotoxin patulin was tested; and the effect of the treatment on the sensory properties of fruits was determined. An efficient protection of lemons was achieved after minimum exposure to a relatively low yeast cell concentration. Apart from lemons, the yeast prevented green mold in grapefruits, mandarins, oranges, and tangerines, implying that it can be used as a broad-range biocontrol agent in citrus. The ability to degrade patulin indicated that strain 146 may be suitable for the control of further Penicillium species. Yeast treatment did not alter the sensory perception of the aroma of fruits. These results corroborate the potential of C. lusitaniae 146 for the control of postharvest diseases of citrus fruits and indicate its suitability for industrial-scale fruit processing.