Characterization of new yeast lipases

Abstract

Previously, we used a simple, sensitive agar plate method to screen lipase activity from 1229 selected cultures, including 508 bacteria, 479 yeasts, 230 actinomycetes and 12 fungi, that covered many genera and species. About 25% of the cultures tested were lipase-positive. We also expanded our screening method to focus specifically on the pH dependence and thermostability of these lipase activities. In this report, we have characterized 25 yeast lipases, obtained from our screening program, on the basis of their positional specificity against triglycerides. Lipase was produced by growing cultures on nutrient medium in the presence of vegetable oil at 25°C for 4 d. Of the 25 new yeast lipases analyzed, 19 showed 1,3-positional specificity and 6 showed random specificity. No 2-positional specific lipases were found. Among those cultures with highest lipase activity are: Candida silvicola NRRL YB-2846 (random); Candida sp. 55 (random); Candida sp. 125 (random); Pichia americana NRRL Y-2156 (1,3-specific); P. muscicola NRRL Y-7005 (random); P. petersanii NRRL YB-3808 (1,3-specific); and Yarrowia lipolytica NRRL YB-423 (random). Characterization of Candida sp. strain 55 lipase on its substrate preference showed that this enzyme hydrolyzed soybean oil triglyceride species LLLn, LLL, LLO, and LLP more readily than LOO, LOP, OOO, LOS, and POO, where L = linoleic, Ln = linolenic, O = oleic, P = palmitic, and S = stearin. JAOCS 74, 1391-1394 (1997).

Esters and their biosynthesis in fermented dairy products: a review

“…rugosa can catalyse ester synthesis by both esterification and transesterification (alcoholysis) under low-water conditions (Linko & Wu, 1996). Thus, the possibility of ester biosynthesis by lipases from dairy yeasts cannot be ruled out, given that many yeasts, including dairy yeasts, possess lipases (Hou, 1997;van den Tempel & Jakobsen, 2000;Addis et al, 2001;Guerzoni et al, 2001;Suzzi et al, 2001).…”

Production of polyol oils from soybean oil by bioprocess: results of microbial screening and identification of positive cultures

“…TLC plates were developed with a two stage development procedure (Hou, 1997;Hou and Lin, 2013) except that benzene was replaced by toluene: (i) toluene/ether/ethyl acetate/acetic acid (80:10:10:1 v/v) was developed with the solvent was 8.5 cm above the origin, and then (ii) hexane/ether/formic acid (80:20:2 v/v) developed in the same direction to the top of the TLC plate. The plate was air-dried before the second development.…”

“…Our previous research established that microbial systems can convert FA to ricinoleic acid-type oxygenated FA, including many bioactive FA such as monohydroxy-, dihydroxy-and trihydroxy-unsaturated FA, tetrahydrofuranyl unsaturated FA, and diepoxy bicyclic unsaturated FA (Hou et al, 1993(Hou et al, , 1998(Hou et al, , 2001Hou, 1994Hou, , 1995Hou, , 1997Gardner et al, 2000;Iwasaki et al, 2002;Hosokawa et al, 2003aHosokawa et al, , 2003bHosokawa et al, , 2003cHou and Hosokawa, 2005;Chang et al, 2007;Suh et al, 2011;Bae et al, 2010). The bio-based polymer industry, however, requires acylglycerol (soybean oil) polyols and not FA polyols.…”

Identification of molecular species of polyol oils produced from soybean oil by Pseudomonas aeruginosa E03-12 NRRL B-59991

“…All samples, including 10 mg/ml soybean oil as standard at the beginning and the end, were run on a Shimadzu model SCL-10A HPLC equipped with a SIL-10AF Auto Injector (Colombia MO). HPLC method was modified from our previous reports (Hou 1997;Lin et al, 2003). A linear gradient starting with 100% methanol going to 100% 2-propanol over 35 min at 1 mL/min flow rate was used for our operation with a Phenomenex 25 cm  4.5 mm, 5 m C18 reversed phase column.…”

“…Our previous research established that microbial systems can convert FA to ricinoleic acid-type oxygenated FA, including many bioactive FA such as monohydroxy-, dihydroxy-and trihydroxy-unsaturated FA, tetrahydrofuranyl unsaturated FA, and diepoxy bicyclic unsaturated FA (Hou, 1994(Hou, , 1995(Hou, , 1997Hou et al, 1998Hou et al, , 2001Gardner et al 2000;Iwasaki et al, 2002;Hosokawa et al, 2003aHosokawa et al, , 2003bHosokawa et al, , 2003cHou and Hosokawa, 2005;Chang et al, 2007;Su et al, 2011;Bae et al, 2010). However, the biobased polymer industry requires acylglycerol (soybean oil) polyols and not FA polyols.…”