Cultivation modes affect the morphology, biochemical composition, and antioxidant and anti-inflammatory properties of the green microalga Neochloris oleoabundans.

Microalgae are considered promising sustainable sources of natural bioactive compounds to be used in biotechnological sectors. In recent years, attention is increasingly given to the search of microalgae-derived compounds with antioxidant and anti-inflammatory properties for nutraceutical or pharmacological issues. In this context, attention is usually focused on the composition and bioactivity of algae or their extracts, while less interest is driven to their biological features, for example, those related to morphology and cultivation conditions. In addition, specific studies on the antioxidant and anti-inflammatory properties of microalgae mainly concern Chlorella or Spirulina. The present work was focused on the characterization of the Chlorophyta Neochloris oleoabundans under two combinations of cultivation modes: autotrophy and glucose-induced mixotrophy, each followed by starvation. Biomass for morphological and biochemical characterization, as well as for extract preparation, was harvested at the end of each cultivation phase. Analyses indicated a different content of the most important classes of bioactive compounds with antioxidant/anti-inflammatory properties (lipids, exo-polysaccharides, pigments, total phenolics, and proteins). In particular, the most promising condition able to prompt the production of antioxidant algal biomass with anti-inflammatory properties was the mixotrophic one. Under mixotrophy, beside an elevated algal biomass production, a strong photosynthetic metabolism with high appression of thylakoid membranes and characteristics of high photo-protection from oxidative damage was observed and linked to the overproduction of exo-polysaccharides and lipids rather than pigments. Overall, mixotrophy appears a good choice to produce natural bioactive extracts, potentially well tolerated by human metabolism and environmentally sustainable.

A newly isolated microalga Chlamydomonas sp. YC to efficiently remove ammonium nitrogen of rare earth elements wastewater.

The aim of this study was to establish a practical approach to remove ammonium nitrogen of rare earth elements (REEs) wastewater by an indigenous photoautotrophic microalga. Firstly, a new microalgal strain was successfully isolated from REEs wastewater and identified as Chlamydomonas sp. (named Chlamydomonas sp. YC). The obtained results showed that microalga could completely remove the NH4+-N of 10% REEs wastewater after 10 days of cultivation; however, the highest NH4+-N removal rate was attained by microalga to treat undiluted REEs wastewater. Then, three cultivation modes including batch, semi-continuous and continuous cultivation methods were developed to evaluate the ability of NH4+-N removal rate by this microalga to treat diluted (10%) and undiluted REEs wastewater. It was found that, Chlamydomonas sp. YC exhibited superior performance towards NH4+-N removal rates (32.75-61.05 mg/(L·d)) by semi-continuous and continuous processes for the treatments of 10% and undiluted REEs wastewater in comparison to the results (19.50-30.38 mg/(L·d) by batch process. Interestingly, under the same treatment conditions, among the three cultivation modes, microalga exhibited the highest removal rates of NH4+-N in undiluted REEs wastewater by semi-continuous (61.05 mg/(L·d)) and continuous (57.10 mg/(L·d) processes. In term of the biochemical analysis, microalgal biomass obtained from the wastewater treatment had 35.40-44.40% carbohydrate and 4.97-6.03% lipid, which could be potential ingredients for sustainable biofuels production. And the highest carbohydrate and lipid productivities attained by Chlamydomonas sp. YC in the continuous mode were 226.36 mg/(L·d) and 32.98 mg/(L·d), respectively. Taken together, the established processes mediated with Chlamydomonas sp. YC via continuous cultivation was the great promising approaches to efficiently remove NH4+-N of REEs wastewater and produce valuable biomass for sustainable and renewable biofuels in a simultaneous manner.

Diversity and composition of the Panax ginseng rhizosphere microbiome in various cultivation modesand ages.

BACKGROUND: Continuous cropping of ginseng (Panax ginseng Meyer) cultivated in farmland for an extended period gives rise to soil-borne disease. The change in soil microbial composition is a major cause of soil-borne diseases and an obstacle to continuous cropping. The impact of cultivation modes and ages on the diversity and composition of the P. ginseng rhizosphere microbial community and technology suitable for cropping P. ginseng in farmland are still being explored. METHODS: Amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions were analyzed for microbial community composition and diversity. RESULTS: The obtained sequencing data were reasonable for estimating soil microbial diversity. We observed significant variations in richness, diversity, and relative abundances of microbial taxa between farmland, deforestation field, and different cultivation years. The bacterial communities of LCK (forest soil where P. ginseng was not grown) had a much higher richness and diversity than those in NCK (farmland soil where P. ginseng was not grown). The increase in cultivation years of P. ginseng in farmland and deforestation field significantly changed the diversity of soil microbial communities. In addition, the accumulation of P. ginseng soil-borne pathogens (Monographella cucumerina, Ilyonectria mors-panacis, I. robusta, Fusarium solani, and Nectria ramulariae) varied with the cropping age of P. ginseng. CONCLUSION: Soil microbial diversity and function were significantly poorer in farmland than in the deforestation field and were affected by P. ginseng planting years. The abundance of common soil-borne pathogens of P. ginseng increased with the cultivation age and led to an imbalance in the microbial community.

Bletilla striata: a review of seedling propagation and cultivation modes.

In recent years, the domestic and international market demand for Bletilla striata has increased rapidly because of its wide use in medical, pharmaceutical, chemical, health, cosmetology, and other fields. The increased demand and a shortage of wild herbal resources have led to the development of large-scale introduction and cultivation programs. Using our research results and the relevant literature, this paper characterizes the original B. striata plant, as well as seedling propagation techniques and its main cultivation modes, and discusses some problems in the B. striata production process. This work will provide a reference for industry development and the promotion of B. striata.

Combination of trace elements and salt stress in different cultivation modes improves the lipid productivity of Scenedesmus spp.

The genus Scenedesmus harbors around 120 species, and some strains have been successfully used for mass culture and biotechnological applications. Considering the potential of this genus as a promising feedstock for production of biofuels, mainly biodiesel, it was evaluated the combined effects of trace elements, salinity stress and different cultivation modes (single batch, semi-continuous, and two-stage batch) on lipid productivity of the freshwater strains S. obliquus BR003 and S. bajacalifornicus BR024. Cultivation of BR003 and BR024 applying culture medium supplemented with trace elements and salt stress sustained a higher production of lipids. However, S. obliquus BR003 and S. bajacalifornicus BR024 showed different concentrations of neutral and total lipids when cultivated in batch-based and semi-continuous modes, and the batch-based modes were preferred for the production of lipids and carbohydrates. Consequently, different cultivation strategies coupled with slight salt stress improve the lipid productivity in Scenedesmus strains.

[Breakthrough in key science and technologies in Dendrobium catenatum industry].

In view of the significant difficulties of propagation, planting and simple product in Dendrobium catenatum(D. officinale)industry development, a series of research were carried out. Genome study showed that D. catenatum is a specie of diploid with 38 chromosomes and 28 910 protein-coding genes. It was identified that specific genes accumulated in different organs at the transcriptome level. We got an insight into the gene regulation mechanism of the loss of the endospermous seed, the wide ecological adaptability and the synthesis of polysaccharides, which provided a theoretical basis for genetic engineering breeding and development and utilization of active pharmaceutical ingredients. The rapid propagation system was established for applying to industrialized production by overcoming breeding problems on seed setting and sprouting, which laid a foundation for artificial cultivation of D. catenatum. And in order to give a clear explanation of genetic variation of important economic traits, we built up the breeding system. Since special varieties of D. catenatum were bred, it helped solve the problem of trait segregation of seedling progeny and support the improvement of D. catenatum industry. The regulation of dynamic variation of target compounds, together with the mechanism of nutrient uptake, was revealed. The breakthrough of key technologies including culture substrates, light regulation and precisely collection was carried out. Several cultivation modes like facility cultivation, original ecological cultivation, cliff epiphytic cultivation, stereoscopic cultivation and potting cultivation were set up. Above all, the goal of cultivating D. catenatum as well as producing good D. catenatum will be achieved.

Breakthrough in key science and technologies in Dendrobium catenatum industry / 中国中药杂志

In view of the significant difficulties of propagation, planting and simple product in Dendrobium catenatum(D. officinale)industry development, a series of research were carried out. Genome study showed that D. catenatum is a specie of diploid with 38 chromosomes and 28 910 protein-coding genes. It was identified that specific genes accumulated in different organs at the transcriptome level. We got an insight into the gene regulation mechanism of the loss of the endospermous seed, the wide ecological adaptability and the synthesis of polysaccharides, which provided a theoretical basis for genetic engineering breeding and development and utilization of active pharmaceutical ingredients. The rapid propagation system was established for applying to industrialized production by overcoming breeding problems on seed setting and sprouting, which laid a foundation for artificial cultivation of D. catenatum. And in order to give a clear explanation of genetic variation of important economic traits, we built up the breeding system. Since special varieties of D. catenatum were bred, it helped solve the problem of trait segregation of seedling progeny and support the improvement of D. catenatum industry. The regulation of dynamic variation of target compounds, together with the mechanism of nutrient uptake, was revealed. The breakthrough of key technologies including culture substrates, light regulation and precisely collection was carried out. Several cultivation modes like facility cultivation, original ecological cultivation, cliff epiphytic cultivation, stereoscopic cultivation and potting cultivation were set up. Above all, the goal of cultivating D. catenatum as well as producing good D. catenatum will be achieved.