Disclosed are an agarase mutant with improved thermal stability and application thereof, belonging to the fields of genetic engineering technology and enzyme engineering. The present disclosure provides an agarase mutant, which is obtained by mutating the amino acid at the 86.sup.th site, the 373.sup.rd site, the 374.sup.th site, the 496.sup.th site, the 507.sup.th site, or the 747.sup.th site of agarase with an amino acid sequence as shown in SEQ ID NO. 1. The agarase mutant provided by the present disclosure improves the thermal stability and the hydrolytic activity of the agarase. Compared with the wild type enzyme, the mutant enzyme shows excellent heat resistance and can be industrially used at a relatively high temperature, so that the utilization rate of agar raw materials and the yield of oligosaccharides from agar are improved, and the mutant enzyme has a good industrial application prospect.

The present invention relates to a heat-resistant agarase and a monosaccharide production method using same. More particularly, in the present invention, a heat-resistant agarase may be used to produce galactose and 3,6-anhydro-L-galactose at high yield by efficiently breaking down agarose or agar without a chemical pretreatment, a neutralization process, or an agarotriose hydrolase treatment process.

The present invention relates to an enzyme complex which the following (i) to (iv) are combined: (i) chimeric beta-agarase formed by a fusion of beta-agarase and the dockerin module of endo--1,4-glucanase-B; (ii) chimeric kappa-carrageenase formed by a fusion of kappa-carrageenase and the dockerin module of endo--1,4-glucanase-B; (iii) chimeric anhydro-galactosidase formed by a fusion of anhydro-galactosidase and the dockerin module of endo--1,4-glucanase-B; and (iv) mini cellulose-binding protein A, and to a method of degrading red algal biomass using the same. According to the present invention, an enzymatic degradation process is applied for the production of agar degradation products, deviating from conventional methods that relied on physical and chemical pretreatment processes. Thus, the present invention will greatly contribute to efficiently converting marine algae into valuable products by use of a convenient, cost-effective, highly efficient and environmentally friendly degradation system while controlling the products.

The present invention relates to a strain that produces neoagarooligosaccharides from agarose, which is a representative polysaccharide constituting red algae, using Saccharomyces boulardii, which is a probiotic yeast, a production method thereof, and a use thereof. The present invention aims to achieve synbiotics through the production of prebiotic substances using probiotic strains and can be used as an intestinal microbial factory.

The present invention relates to agarooligosaccharide hydrolase and a method for producing 3,6-anhydro-L-galactose and galactose from agarose by using the same. More specifically, the production yield of 3,6-anhydro-L-galactose and galactose from agarose, that is, the saccharification yield, is improved by using -agarooligosaccharide hydrolase having an agarotriose hydrolytic activity.

The present invention provides a -agarase, a composition containing the same and applications thereof. The present -agarase provides the field a novel alternative and is favorable for the industrial utilities of the hydrolysis products of agarose. Furthermore, the present agarase is particularly modified for heterologous production by prokaryotic expression systems, and thereby is favorable for commercial use.

The present invention provides a -agarase, a composition containing the same and applications thereof. The present -agarase provides the field a novel alternative and is favorable for the industrial utilities of the hydrolysis products of agarose. Furthermore, the hydrolysis product of agarose by the present -agarase has high purity of neoagarotetraose therefore the present -agarase is especially useful for the neoagarotetraose's utilities in the field.

The present invention provides a -agarase, a composition containing the same and applications thereof. The present -agarase provides the field a novel alternative and is favorable for the industrial utilities of the hydrolysis products of agarose. Furthermore, the hydrolysis product of agarose by the present -agarase has high purity of neoagarotetraose therefore the present -agarase is especially useful for the neoagarotetraose's utilities in the field.

An engineered bacterium based on Bacillus subtilis is provided, a genome of the engineered bacterium includes a multi-enzyme element, and the multi-enzyme element comprises a class I -agarase element (E1 element), a class II -agarase element (E2 element), and an -neoagaro-diohydrolase element (E3 element). The engineered bacterium integrates agarase genes into the Bacillus subtilis genome, achieving cascade catalysis of agarose to produce active oligosaccharides and monosaccharides, thereby utilizing the biological activity of these active oligosaccharides and monosaccharides to treat intestinal inflammation. An engineered biofilm based on Bacillus subtilis is also provided, which includes the engineered bacterium and its secretions. Furthermore, a living material for multi-enzyme display and treatment of intestinal inflammation in mice is also provided, which includes the engineered bacterium or the engineered biofilm.

The present invention relates to a method of producing neoagarotetraose (NA4) and neoagarohexaose (NA6) with high purity in large amounts by liquefaction of the substrate agarose using a thermostable GH16B -agarase derived from a novel agarolytic bacterium Cellvibrio sp. KY-GH-1 deposited under accession number KCTC 13629BP. The method of producing neoagarotetraose (NA4) and neoagarohexaose (NA6) with high purity in large amounts by liquefaction of the substrate agarose using a thermostable GH16B -agarase derived from a novel agarolytic bacterium Cellvibrio sp. KY-GH-1 deposited under accession number KCTC 13629BP according to the present invention may effectively produce NA4 and NA6 with high purity in large amounts by efficiently performing liquefaction of the substrate agarose, because the thermostable GH16B -agarase exhibits excellent enzyme activity at a high temperature equal to or higher than the agarose gelling temperature and has long-term thermal stability even at high temperatures.