The present invention provides a method for producing an alcohol comprising: (a) admixing a tripeptidyl peptidase, predominantly having exopeptidase activity, with a feedstock or a fraction thereof before, during or after fermentation of said feedstock or a fraction thereof; and (b) recovering an alcohol. Also provided are uses of a tripeptidyl peptidase and by-products of alcohol production obtainable by the method of the invention.

An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

A C4-dicarboxylic acid transporter and its encoding gene C4mt gene can increase oil yield of Mucor circinelloides, the C4mt gene may be cloned from the high-yield M. circinelloides WJ11, and the C4mt gene is transformed into M. circinelloides deficient strain Mu402, the C4mt gene can be integrated into the genome of M. circinelloides by homologous recombination to obtain recombinant strain Mu-C4mt. The total fatty acid content of the Mu-C4mt strain can be increased by 25.30% and the intracellular lipid content may reach up to 16.34% of the dry biomass.

The present invention relates to a process for simultaneous production of citric acid and cellulolytic enzymes. The batch process comprising (i) adding slurry of a pre-treated lignocellulosic biomass or cellulose in a fermentation media; (ii) inoculating 10% (v/v) active liquid seed culture of Penicillium funiculosum MRJ-16 in the fermentation media of step (i); (iii) subjecting the culture of step (ii) to fermentation in an aerated fermenter at a temperature of 28-33° C. for a duration of 96 hours; and (iv) collecting enzyme broth after fermentation of step (iii) to obtain citric acid and cellulolytic enzymes. The batch and fed-batch process of the present invention results in high titer production of citric acid and cellulolytic enzymes in a single step and using single microbial strain.

The present invention relates to a process for simultaneous production of citric acid and cellulolytic enzymes. The batch process comprising (i) adding slurry of a pre-treated lignocellulosic biomass or cellulose in a fermentation media; (ii) inoculating 10% (v/v) active liquid seed culture of Penicillium funiculosum MRJ-16 in the fermentation media of step (i); (iii) subjecting the culture of step (ii) to fermentation in an aerated fermenter at a temperature of 28-33° C. for a duration of 96 hours; and (iv) collecting enzyme broth after fermentation of step (iii) to obtain citric acid and cellulolytic enzymes. The batch and fed-batch process of the present invention results in high titer production of citric acid and cellulolytic enzymes in a single step and using single microbial strain.

The present disclosure discloses a thermophilic recombinant type II pullulanase and the application thereof, and belongs to the technical field of genetic engineering. The present disclosure obtains a thermophilic recombinant type II pullulanase by heterologously expressing type II pullulanase in Escherichia coli. Its optimum pH is 6.6, it has better pH tolerance under the conditions of pH 5.8-8.0, and its optimum temperature is 95° C. After incubating at 95° C. for 10 h, the remaining enzyme activity is greater than 50%. It can exhibit higher specific enzyme activity under strong reducing conditions. For example, adding DTT to the culture environment can increase the specific enzyme activity of Sumo-Pul.sub.Py by 237.2%. The present disclosure also provides the combined truncation mutant Δ28N+Δ791C of type II pullulanase Sumo-Pul.sub.Py. The specific enzyme activity of the enzyme mutant is 32.18±0.92 U/mg, which is 5.99 times as high as that of the wild-type enzyme, thereby having important industrial application value and potential.

The present invention provides an acid-tolerant Saccharomyces cerevisiae strain and use thereof. By using exogenously added malic acid as a stress, an acid-tolerant mutant S. cerevisiae strain MTPfo-4 is obtained by directed evolution screening in the laboratory, which tolerates a minimum pH of 2.44. The mutant strain MTPfo-4, tolerant to multiple organic acids, has an increased tolerance to exogenous malic acid of up to 86.6 g/L. The mutant strain MTPfo-4 obtained is further identified. The mutant strain grows stably and well, and can tolerate a variety of organic acids (lactic acid, malic acid, succinic acid, fumaric acid, citric acid, gluconic acid, and tartaric acid). It also has a strong tolerance to inorganic acids (HCl and H.sub.3PO.sub.4). This is difficult to achieve in the existing research and reports of S. cerevisiae. The strain is intended to be used as an acid-tolerant chassis cell factory for producing various short-chain organic acids.

The invention relates to a process for the preparation of a sugar product from lignocellulosic material, comprising the following steps: a) optionally pre-treatment of the ligno-cellulosic material; b) optionally washing of the optionally pre-treated ligno-cellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pre-treated ligno-cellulosic material using an enzyme composition comprising at least two cellulase and whereby the enzyme composition at least comprises GH61; and d) optionally recovery of a sugar product;
wherein during part of the time of the enzymatic hydrolysis, oxygen is added to the ligno-cellulosic material and during part of the time of the enzymatic hydrolysis less oxygen is added to the ligno-cellulosic material compared to the other part of the time of the enzymatic hydrolysis, preferably no oxygen is added to the ligno-cellulosic material.

The invention relates to a process for the preparation of a sugar product from lignocellulosic material, comprising the following steps: a) optionally pre-treatment of the ligno-cellulosic material; b) optionally washing of the optionally pre-treated ligno-cellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pre-treated ligno-cellulosic material using an enzyme composition comprising at least two cellulase and whereby the enzyme composition at least comprises GH61; and d) optionally recovery of a sugar product;
wherein during part of the time of the enzymatic hydrolysis, oxygen is added to the ligno-cellulosic material and during part of the time of the enzymatic hydrolysis less oxygen is added to the ligno-cellulosic material compared to the other part of the time of the enzymatic hydrolysis, preferably no oxygen is added to the ligno-cellulosic material.