Abstract:

The processing of citrus canning produces a large amount of pectin sludge, which was converted into a cultivation substrate using the rapid putrefaction of efficient strains to achieve the resourceful utilisation of pectin sludge that is difficult to be treated with high water-holding capacity. The results showed that the pectinase activity of Trichoderma koningii LZ51 reached 684 U·mL^-1; straw pectin substrate (M1) and vermiculite pectin substrate (M2) were produced by mixing and fermenting pectin sludge with straw and vermiculite, respectively, and it was found that the germination and seedling development of cherry red radish, large-leafed spinach and four-season chive were better than that under vermiculite substrate (CK) culture. both had significantly higher performance than vermiculite substrate (CK). In particular, M1 increased the germination rate of the three vegetables by an average of 5% compared with CK; at the seedling stage, M1 produced a 30% increase in fresh weight of cherry red radish compared with CK, and a 50% increase in the fresh weight of large-leaf spinach compared with CK. The use of pectin sludge and straw mixed fermentation to prepare a new type of cultivation substrate opens up a new utilisation pathway for the resourceful utilisation of pectin sludge from canning processing, which has a promising market prospect.

Key words: pectin sludge, substrate fermentation, pectin-degrading bacteria, seedling production