IntroductionChinese cabbage (Brassica rapa var. pekinensis, hereinafter referred to as cabbage) is a kind of very common vegetable, which is widely planted in Asia and Europe. In autumn and winter, fresh but surplus cabbage is usually made into fermented cabbage, i.e. suan cai (sour vegetable in Chinese) which is nutritious and popular. Fermented cabbage is a very traditional and local food in Asia, especially in northeast China. The production process of fermented cabbage is similar to kimchi in Korea or sauerkraut in Germany, which relies on the fermentation by LAB (lactic acid bacteria). During the traditional producing process, cabbage is soaked into salt water at ambient temperature for weeks. Naturally occurring LAB transferred reducing sugar to organic acids, amino acids and other flavor substances (Wu et al. 2012). The sensory quality of fermented vegetable is unstable due to the variety in species and amount of epiphytic LAB. Meanwhile, nitrite produced by nitrate reducing bacteria during vegetable fermentation potentially threat consumers' health (Paik and Lee 2014).The use of LAB as starter cultures has been considered to ferment fresh vegetables into quality uniform and healthy food in decade. Several LAB such as Leuconostoc mesenteroides, Leu. citreum, and Lactobacillus plantarum have been applied in kimchi fermentation for quality development (Leal-Sánchez et al. 2003;Cho et al. 2014;Jo et al. 2014). LAB strain Lb.delbrueckii and Lb.paracasei have been used as mixed starter cultures to improve the characteristics of fermented cabbage (Han, Yi et al. 2014). The D. Zhao et al. 326 LAB inoculated into the vegetable fermentation produces more nutritive metabolites including lactate, acetate, amino acids, mannitol, and so on (Jung et al. 2012;Jo et al. 2014). Moreover, starter LAB generates more acidic conditions which results in inhibition of pathogenic bacteria (Chang and Chang 2011) and decomposition of nitrite Paik and Lee 2014).Though the bacterial succession and metabolites production during kimchi fermentation with LAB starter is relatively well studied by means of high-throughput sequencing and metabolomics techniques (Jung et al. 2012;, the impact of LAB starter on characteristics of fermented cabbage is barely known. In this research, Lb.paracasei HD1.7 was applied in cabbage fermentation as a starter culture. This strain was isolated from the liquid sample during cabbage fermentation which permitted its good compatibility as a starter (Lei et al. 2007). Several studies have been conducted on strain HD1.7, such as the purification and characteristics of bacteriocin (Ge et al. 2009), the optimization of bacteriocin producing medium (Ge et al. 2011a), the establishment of genetic transformation system (Ge et al. 2011b) and the mechanism of quorum sensing (Ge et al. 2011c gene was amplified and copy numbers were calculated based on the method of (Jung et al. 2011). Although the copy numbers determined by this method were not exactly equal to the cell numbers, we employed the PCR method becaus...

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Two pectinase-producing strains, HDYM-01 and HDYM-02, were added into retting tanks to accelerate the water-retting of flax after they were amplified in liquid medium. The results show that the yields of fiber flax retted with bacteria addition are higher than the control, and the difference is significant with F test. When reusing the retting water to the next tank to perform the water-retting with bacteria addition, the yields of fiber flax are also higher and the difference is significant with F test. The retting time would be shortened for 24 hr and the flax strength is raised for 20-30 Newton (N) with bacteria addition method and reusing retting water method.

Bacillus licheniformisHDYM-03 was isolated from flax-retting water. In this research, the production of flax-degumming enzymes by this strain was investigated in four medium, whose sole carbon source was beef extract peptone (BP), pectin (PEC), konjac powder (KGM) and carboxymethylcellulose sodium (CMC), respectively. In PEC medium, the production of pectinase (455.06 U/mL) and polygalacturonase (540.32 U/mL) is higher than that in other medium. In KGM medium, the mannanase reach the highest activity 193.33 U/mL. The production of xylanase and cellulase is extremely lower and could be ignored in all of the four medium. The results show that the production of flax-degumming enzymes by this strain could be significantly induced by flax colloid.B.licheniformisHDYM-03 suggest an applicable potential in flax-retting industry.