Formation of Esters by Yeast. II. Investigations with Cellular Suspensions of Hansenula Anomala

Abstract

In a previous paper we reported (21) Peel differ in several respects. This may be due to difference in strain used, or to the fact that our results were based on analysis of cellular suspensions incubated for longer periods of time. Materials and methodsThe strain of H. anomrala var. longa type B (Naegeli) Dekker, was grown in medium I, TABACHNICK and JOSLYN (21) witlh 1%o of glucose as carbon source. The inedium inoculated with a 107% by volume of a 24-hour growing culture was shaken (7.5 cmu. stroke, 94 cycles per ininute) for 24 hours at room temperature (23 to 26°C). To prevent excess foaming, 0.3 ml. of sterile soy-bean oil was added per liter of shake culture. After harvesting the cells by centrifuging and washing, aseptic technique was no longer observed. Cell nitrogen was determined by the micro-Kjeldahl method.Preliminary experiments showed that, as reported also by PEEL (18), ethanol alone could serve as substrate for ethyl acetate production and that acetate was not necessary. Acetic acid at a concentration of 0.05 I\1 (at pH 3) was toxic. Highest yields of ethyl acetate were obtained in a 20-ml. cell suspension containing 10 ml\I of ethanol, 0.1 'I phosphate buffer at pH of about 3, and at a cell density equivalent to 4.5 to 5.5 mg. of cell nitrogen per 20 ml., shaken in a cotton-stoppered 125-ml. Erlenmeyer flask for 18 to 24 hours at room temperature (23 to 26°C). Unless otherwise stated these conditions were used in subsequent experiments. PEEL (18) reported opti-1 Present address: Northern Division,

Formation of ethyl acetate by Kluyveromyces marxianus on whey: Influence of aeration and inhibition of yeast growth by ethyl acetate

“…17 g/L. This is in accordance with the observation of Tabachnick et Joslyn who detected the acute toxicity of ethyl acetate for P. anomala in a range between 12.3 and 17.6 g/L. Ethyl acetate seems to be significantly more toxic than ethanol; the stop of growth of K. marxianus was found at ethanol concentrations between 50 to 100 g/L .…”

“…For bacteria, this ability is quite common , but reported utilization of ethyl acetate by yeasts is, however, often doubtful since disappearance of ester cannot be equated with microbial uptake. Evidenced degradation of ethyl acetate by yeasts was only described for P. anomala and H. mrakii while degradation of ethyl acetate by K. marxianus DSM 5422 can be ruled out .…”

“…Tabachnick et Joslyn tested the inhibitory action of ethyl acetate on Pichia anomala which is well known as a potent producer of this ester . The toxic concentration of ethyl acetate for this yeast appeared to lie between 12.3 and 17.6 g/L which is more reliable since the use of rubber‐stoppered shake flasks prevented evaporation of ester.…”

From Eat to trEat: Engineering the mitochondrial Eat1 enzyme for enhanced ethyl acetate production in Escherichia coli

“…The better performance of Wan Eat1 compared to Kma Eat1 may also originate from its temperature optimum. The yeast W. anomalus is routinely cultivated at temperatures between 25-30 °C (Tabachnick and Joslyn, 1953;Fredlund et al, 2004;Kurita, 2007;Sabel et al, 2014). In contrast, the yeast K. marxianus produced ethyl acetate more efficiently at 42 °C compared to lower temperatures (Urit et al, 2013).…”

Nutrient Effects on Biocontrol of Penicillium roqueforti by Pichia anomala J121 during Airtight Storage of Wheat

“…When 0.6 ml of ethyl acetate was added to the atmosphere above a plate without ethanol, the mean dry weight of the P. roqueforti colony decreased to 7.3 Ϯ 2.8 mg. When ethanolcontaining agar was combined with ethyl acetate in the atmosphere, the colony dry weight was further reduced to 4.7 Ϯ 1.5 mg. P. anomala itself is able to grow at 10% (wt/vol) ethanol (9) and can survive in 0.2 M ethyl acetate (28).…”