Selection of Optimal Medium for Cultivation of Idesia polycarpa var.vestita Seedlings in the Industrialized Nursery Process

Idesia polycarpa Maxim.var.vestita Diels is an important oil plant with high economic value.In order to improve seed germination and to cultivate high quality seedlings,we set out to identify an optimal medium for its seedling growth in a plastic cave tray(plug seedling).In this study,four different media including M_(1)(soil),M_(2)(peat∶perlite=2∶1),M_3(peat),and M_4(peat∶perlite∶vermiculite=2∶1∶1)were tested in industrialized plug seedlings.The seedling growth of Idesia polycarpa var.vestita including plant height,crown diameter,leaf number,ground diameter,the relative chlorophyll contents of leaves,etc.was measured.The results indicated that the medium M_(2) was the best for increasing seedling height,crown diameter,leaf counts,ground diameter,and the relative chlorophyll contents of leaves.Therefore,medium M_(2) is recommended in the industrialized nursery process for the seedling growth of Idesia polycarpa var.vestita.

Valorisation of fruit waste for enhanced exopolysaccharide production by Xanthomonas campestries using statistical optimisation of medium and process

The aim of this research work was to enhance the fermentative production of exopolysaccharide(EPS)with mixed fruit waste as a key substrate.Xanothomonas campestries was isolated from spoiled orange and its EPS production efficiency was determined using EPS medium.Prior to optimisation,the production was 3.4 g/L,upon optimizing the medium the production improved to 9.2 g/L.The medium formulation was studied by sequential addition of medium components and replacement of sugar with mixed fruit waste.In formulated medium,the production enhanced to 11.1 g/L.For further optimisation,the response surface methodology was used,which resulted in the enhancement of production to 14.5 g/L.The scale-up study was undertaken in a 10 L shake flask and fermenter.In 10 L flask EPS,production was 14.45 g/L in 100 h,whereas in 10 L fermenter it was 21.10 g/L in 60h only.The optimisation studies gave nearly 500%(6.2fold)enhanced EPS production and dwindle in fermentation time.Replacement of sucrose with fruit waste extract made the process environment-friendly;omission of L-cystine and use of 50%reduced amount of sodium acetate in the medium lowered the production cost of EPS.The developed process resulted in the utilization of fruit waste and was also useful in solving the fruit waste disposal problem.

Cultivation of halophilic archaea(class Halobacteria)from thalassohaline and athalassohaline environments

As a group,the halophilic archaea(class Halobacteria)are the most salt-requiring and salt-resistant microorganisms within the domain Archaea.Halophilic archaea flourish in thalassohaline and athalassohaline environments and require over 100–150 g/L NaCl for growth and structural stability.Natural hypersaline environments vary in salt concentration,chemical composition and pH,and occur in climates ranging from tropical to polar and even under-sea.Accordingly,their resident haloarchaeal species vary enormously,as do their individual population compositions and community structures.These diverse halophilic archaeal strains are precious resources for theoretical and applied research but assessing their taxonomic and metabolic novelty and diversity in natural environments has been technically difficult up until recently.Environmental DNA-based high-throughput sequencing technology has now matured sufficiently to allow inexpensive recovery of massive amounts of sequence data,revealing the distribution and community composition of halophilic archaea in different hypersaline environments.While cultivation of haloarchaea is slow and tedious,and only recovers a fraction of the natural diversity,it is the conventional means of describing new species,and provides strains for detailed study.As of the end of May 2020,the class Halobacteria contains 71 genera and 275 species,49.8%of which were first isolated from the marine salt environment and 50.2%from the inland salt environment,indicating that both thalassohaline and athalassohaline environments contain diverse halophilic archaea.However,there remain taxa that have not yet been isolated in pure culture,such as the nanohaloarchaea,which are widespread in the salt environment and may be one of the hot spots in the field of halophilic archaea research in the future.In this review,we focus on the cultivation strategies that have been used to isolate extremely halophilic archaea and point out some of the pitfalls and challenges.