Effects of Funneliformis mosseae on the utilization of organic phosphorus in Camellia oleifera Abel.

Arbuscular mycorrhizal (AM) fungi play an important role in the acquisition of phosphorus (P) by plants. The external hyphae of AM fungi function as an extension of plant roots and may downregulate related functions in the roots. It is not clear whether the ability of AM fungi to mineralize organic P affects root phosphatase activities. A pot experiment was conducted to investigate the effect of Funneliformis mosseae on soil organic P mineralization under phytate application and to explore root phosphatase activities, P uptake, and growth in Camellia oleifera Abel. The plants and their growth substrates were harvested 4 and 8 months after planting. The results showed that organic P application had no effect on the total dry mass of nonmycorrhizal plants, but differences in dry mass under P application were observed in mycorrhizal plants in both harvests. Inoculation with F. mosseae increased soil acid phosphatase, phytase, and alkaline phosphatase activities and reduced the soil organic P content. Mycorrhizal plants had higher root activity, shoot and root P contents and root acid phosphatase and phytase activities than nonmycorrhizal plants irrespective of organic P application. In conclusion, AM fungi enhanced the mineralization of soil organic P and positively affect root phosphatase activities.

Endophytic fungi from the branches of Camellia taliensis (W. W. Smith) Melchior, a widely distributed wild tea plant.

Camellia taliensis (W. W. Smith) Melchior is a wild tea plant endemic from the west and southwest of Yunnan province of China to the north of Myanmar and is used commonly to produce tea by the local people of its growing areas. Its chemical constituents are closely related to those of C. sinensis var. assamica, a widely cultivated tea plant. In this study, the α diversity and phylogeny of endophytic fungi in the branches of C. taliensis were explored for the first time. A total of 160 fungal strains were obtained and grouped into 42 species from 29 genera, which were identified based on rDNA internal transcribed spacer sequence analysis. Diversity analysis showed that the endophytic fungal community of the branches of C. taliensis had high species richness S (42), Margalef index D' (8.0785), Shannon-Wiener index H' (2.8494), Simpson diversity index DS (0.8891), PIE index (0.8947) and evenness Pielou index J (0.7623) but a low dominant index λ (0.1109). By contrast, that in the branches of C. taliensis had abundant species and high species evenness. Diaporthe tectonigena, Acrocalymma sp. and Colletotrichum magnisporum were the dominant endophytic fungi. The phylogenetic tree was established by maximum parsimony analysis, and the 11 orders observed for endophytic fungi belonging to Ascomycota and Basidiomycota were grouped into 4 classes.

Bioactive Exopolysaccharides Reveal Camellia oleifera Infected by the Fungus Exobasidium gracile Could Have a Functional Use.

Camellia oleifera is an important Chinese commercial crop. Camellia oleifera can display abnormal leaves due to infection by the parasitic fungus Exobasidium gracile. Exobasidium gracile was isolated from infected leaves and used in fermentation, and exopolysaccharides EP0-1 and EP0.5-1 were purified from the fermentation broth. EP0-1 was an alkaline polysaccharide consisting mainly of the linkages α-d-Manp(1→, →2)-α-d-Manp(1→ and →6)-α-d-Manp(1→, →3)-α-d-Glcp(1→ and→4)-α-d-Glcp(1→, terminal ß-d-Galf, (1→5)-ß-d-Galf, and terminal ß-D-GlcN(1→. EP0.5-1 was an acidic galactofuranose-containing polysaccharide. It contained the linkages of α-d-Manp(1→, →2)-α-d-Manp(1→, →6)-α-d-Manp(1→,→2, 6)-α-d-Manp(1→, →4)-α-d-Glcp(1→, and →4)-α-d-GlcUA(1→. Galactofuranose linkages were composed of terminal ß-d-Galf, (1→6)-ß-d-Galf and (1→2)-ß-d-Galf. Exobasidium gracile exopolysaccharides displayed significant immunoregulatory activity by activating macrophages. This research indicates that infected leaves from Camellia oleifera including the exopolysaccharides produced by the parasitic fungus Exobasidium gracile by are worth further investigation as a functional product.

Effects of fermentation on the hemolytic activity and degradation of Camellia oleifera saponins by Lactobacillus crustorum and Bacillus subtilis.

The saponins, as components of tea seed meal, are undesirable hemolytic components and should be degraded for reducing their hemolytic activity in order to be used in animal feed. In this study, ß-glucuronidase was verified to be a potent hydrolase of tea seed saponins to reduce their hemolytic activity and a ß-glucuronidase-producing Lactobacillus crustorum strain was screened from raw bovine milk. Next, solid-state fermentation with the isolated L. crustorum and a Bacillus subtilis natto strain, which can produce cellulase and hence improve the fermentation performance of tea seed meal, was carried out for detoxification of tea seed meal. The 50% hemolytic dosage (HD50) value of tea seed saponins was increased from 6.69 to 27.43 µg mL-1. The results of LC-MS analysis showed that the percentage of saponin aglycones increased from 30.95 to 84.25% after the fermentation. According to the roles of sugar moieties in hemolytic activity, and the enzymatic hydrolysis characteristics of ß-glucuronidase, the degradation of tea seed saponins from glucosides to aglycones may contribute to the reduction of hemolytic activity. Therefore, tea seed meal may be used as animal feed after fermentation with the tested saponin-degrading microbial strains.

Change in tea polyphenol and purine alkaloid composition during solid-state fungal fermentation of postfermented tea.

The aim of this study was to evaluate tea polyphenol and purine alkaloid contents of pu-erh tea (Camellia assamica) in a fermentation solid system with Aspergillus niger and Aspergillus fumigatu. In addition, the objective was to find the major intermediate product during fermentation by HPLC-MS(n) analysis. The results showed the change of catechin, ester-catechins and gallic acid by quantitative analysis. In the early stages, the contents of ester-catechins were lightly increased. Then, ester-catechins were gradually degraded to produce catechins and gallic acid. Furthermore, a major metabolic intermediate compound of catechins was observed and elucidated by HPLC-DAD-MS(n) analysis. This study provided a reliable dynamic data description and metabolic pathway of tea polyphenols for postfermented pu-erh tea.