The present invention relates to Candida strains comprising a mutation or deletion in the first and/or second XYL2 allele which can be used for producing one or more sugar alcohols from a lignocellulosic feedstock. The preferred sugar alcohol is xylitol.

A long-chain composition has at least one long-chain alkane selected from the group consisting of C9-18 linear or branched alkanes and at least one long-chain carboxylic acid selected from the group consisting of C9-18 linear or branched, saturated or unsaturated aliphatic monocarboxylic acids. The mass ratio of the long-chain alkane to the long-chain carboxylic acid ranges from 1:1 to 40:1. The long-chain composition has a higher fermentation degree or higher substrate utilization rate and the like, when used as a starting material in the production of long-chain dibasic acids via fermentation.

The present invention relates to a process for valorization of low-cost alkane rich feedstock. More specifically, the present invention relates to the selective conversion of alkane rich kerosene to value-added products like mono/dicarboxylic acid, fatty acids and biosurfactants using mutant yeast strain and a heterogenous nano-catalyst. The present invention also provides a mutant yeast strain for selective conversion of alkane rich refinery stream from a substrate containing hydrocarbons. The mutant yeast strain of the present invention is able to consume the sulfur content in the feed and results in the desulfurization of the alkane rich feedstock.

Provided are a Candida tropicalis strain Am2525, with the preservation number thereof being CCTCC NO: M 2019419, and a method for producing long-chain dicarboxylic acids by means of fermenting the strain. The method for producing the long-chain dicarboxylic acids comprises preparing a seed solution by means of the Candida tropicalis strain Am2525 and producing the long-chain dicarboxylic acids via fermentation of the seed solution. Compared with the parent, the Candida tropicalis strain Am2525 has an enhanced resistance to the toxicity of a substrate decane, improves the productivity of long-chain dicarboxylic acids, reduces the cost of production, subsequent separation and purification are simple, and the fermentation production process is easy to implement on a large scale.

The present invention relates to a Candida tropicalis cell line, which comprises a mutant gene, having improved tolerance for cytotoxicity of stromal cells, and a method for producing dicarboxylic acid using the Candida tropicalis cell line. The Candida tropicalis cell line for producing dicarboxylic acid developed according to the present invention has improved tolerance for existing stromal toxicity as well as significantly improved efficiency for producing dicarboxylic acid compared to existing cell lines, thus can be used in biological production of dicarboxylic acid and is expected to have high industrial utility.

The present invention relates to Candida strains comprising a mutation or deletion in the first and/or second XYL2 allele which can be used for producing one or more sugar alcohols from a lignocellulosic feedstock. The preferred sugar alcohol is xylitol.

There is provided a gene cassette for disruption of at least one target gene in a yeast cell, wherein the gene cassette comprises: (d) a URA3 gene capable of being used as a marker gene; (e) at least one gene disruption auxiliary (gda) sequence; and (f) an upstream and a downstream sequences of the target gene,
wherein the gda sequence is at least 300 to 600 bp in length and selected from within the nucleotide sequence of SEQ ID NO:39.

Provided are a Candida tropicalis strain Am2525, with the preservation number thereof being CCTCC NO: M 2019419, and a method for producing long-chain dicarboxylic acids by means of fermenting the strain. The method for producing the long-chain dicarboxylic acids comprises preparing a seed solution by means of the Candida tropicalis strain Am2525 and producing the long-chain dicarboxylic acids via fermentation of the seed solution. Compared with the parent, the Candida tropicalis strain Am2525 has an enhanced resistance to the toxicity of a substrate decane, improves the productivity of long-chain dicarboxylic acids, reduces the cost of production, subsequent separation and purification are simple, and the fermentation production process is easy to implement on a large scale.

A long-chain composition has at least one long-chain alkane selected from the group consisting of C9-18 linear or branched alkanes and at least one long-chain carboxylic acid selected from the group consisting of C9-18 linear or branched, saturated or unsaturated aliphatic monocarboxylic acids. The mass ratio of the long-chain alkane to the long-chain carboxylic acid ranges from 1:1 to 40:1. The long-chain composition has a higher fermentation degree or higher substrate utilization rate and the like, when used as a starting material in the production of long-chain dibasic acids via fermentation.