Improved production of jiangxienone in submerged fermentation of Cordyceps jiangxiensis under nitrogen deficiency.

Jiangxienone produced by Cordyceps jiangxiensis exhibits significant cytotoxicity and good selectivity against various human cancer cells, especially gastric cancer cells. In this work, the effect of nitrogen deficiency on the accumulation of jiangxienone and the transcription levels of jiangxienone biosynthesis genes was studied in submerged fermentation of C. jiangxiensis. Results showed that accumulation of jiangxienone was improved under nitrogen deficiency condition. A maximal jiangxienone content of 3.2 µg/g cell dry weight was reached at 5 mM glutamine, and it was about 8.9-fold higher than that obtained at 60 mM glutamine (control). The transcription levels of the biosynthetic pathway genes hmgr and sqs and the nitrogen regulatory gene areA were upregulated by 7-, 14-, and 28-fold, respectively, in culture with 5 mM glutamine compared to the control. It was hypothesized that the jiangxienone biosynthesis may involve the mevalonate pathway in C. jiangxiensis. Taken together, our study indicated that nitrogen deficiency is an efficient strategy for enhancing jiangxienone accumulation in submerged fermentation of C. jiangxiensis, which is useful for further understanding the regulation of jiangxienone biosynthesis.

Further improvement in ganoderic acid production in static liquid culture of Ganoderma lucidum by integrating nitrogen limitation and calcium ion addition.

To further improve the ganoderic acid (GA) production, a novel integrated strategy by combining nitrogen limitation and calcium ion addition was developed. The effects of the integrated combination on the content of GA-T (one powerful anticancer compound), their intermediates (squalene and lanosterol) and on the transcription levels of GA biosynthetic genes in G. lucidum fermentation were investigated. The maximum GA-T content with the integrated strategy were 1.87 mg/ 100 mg dry cell weight, which was 2.1-4.2 fold higher than that obtained with either calcium ion addition or nitrogen limitation alone, and it is also the highest record as ever reported in submerged fermentation of G. lucidum. The squalene content was increased by 3.9- and 2.2-fold in this case compared with either individual strategy alone. Moreover, the transcription levels of the GA biosynthetic genes encoding 3-hydroxy-3-methyglutaryl coenzyme A reductase and lanosterol synthase were also up-regulated by 3.3-7.5 and 1.3-2.3 fold, respectively.

Partial root-zone drying subsurface drip irrigation increased the alfalfa quality yield but decreased the alfalfa quality content.

Water shortage seriously restricts the development of grassland agriculture in arid land and dramatically impacts alfalfa (Medicago sativa L.) quality content and hay yield. Reasonable irrigation methods have the potential to enhance the alfalfa quality content, hay yield, and thus quality yield. Whether partial root-zone drying subsurface drip irrigation (PRDSDI) improves the alfalfa quality yield, quality content, and hay yield is still unknown compared with conventional subsurface drip irrigation (CSDI). The effects of PRDSDI compared with that of CSDI and the interaction with irrigation volume (10 mm/week, 20 mm/week, and 30 mm/week) on the alfalfa quality yield were investigated in 2017-2018 and explained the change in quality yield with the alfalfa quality content and hay yield. Here, the results showed that PRDSDI did not increase the alfalfa quality yield in 2 years. PRDSDI significantly increased acid detergent fiber by 13.3% and 12.2% in 2018 with 10-mm and 20-mm irrigation volumes and neutral detergent fiber by 16.2%, 13.2%, and 12.6% in 2017 with 10-mm, 20-mm, and 30-mm irrigation volumes, respectively. PRDSDI significantly decreased the crude protein by 5.4% and 8.4% in 2018 with 10-mm and 20-mm irrigation volumes and relative feed value by 15.0% with 20-mm irrigation volume in 2017 and 9.8% with 10-mm irrigation volume in 2018, respectively. In addition, PRDSDI significantly increased the alfalfa average hay yield by 49.5% and 59.6% with 10-mm and 20-mm irrigation volumes in 2018, respectively. Our results provide a counterexample for PRDSDI to improve crop quality. Although there was no significant improvement in average quality yield by PRDSDI, the positive impact of average hay yield on quality yield outweighed the negative impact of quality content. Thus, it has the potential to improve quality yields. The novel findings regarding the effects of PRDSDI on quality yield are potentially favorable for the forage feed value in water-limited areas.

Revealing the real-time diversity and abundance of small mammals by using an Intelligent Animal Monitoring System (IAMS).

It is challenging to reveal the real-time spatio-temporal change of diversity and abundance of animals in natural systems by using traditional methods. The rapid advancement of new technologies such as the Internet of Things, artificial intelligence, and big-data processing, provide opportunities for developing novel technologies for monitoring biodiversity and population abundance of animals with high efficacy and accuracy. In this study, by using a recently developed Intelligent Animal Monitoring System, named "Vector Intelligent Monitoring System (VIMS)", we investigated the real-time diversity and abundance of small mammals in the Banruosi forest, Dujiangyan region, southwest China. To make a comparison of the VIMS with traditional methods, we also surveyed the diversity and abundance of small mammals using wired live traps. Compared to live traps, the VIMS has several advantages such as automatic data collection, intelligent identification of species, data visualization, whole-day and all-weather operation, little disturbance to animals, real-time monitoring, and is capable of revealing more small mammal species. However, the VIMS also has several disadvantages over live traps such as lower trapping efficiency and being more expensive than live traps. Our results suggest that the VIMS can be a complementary method to traditional ones in monitoring the real-time spatio-temporal change of diversity and abundance of small mammals (especially rare species). In addition, the VIMS is useful in monitoring other small animals like small carnivores, birds, amphibians, and reptiles.

Responses of Biogeochemical Characteristics and Enzyme Activities in Sediment to Climate Warming under a Simulation Experiment in Geographically Isolated Wetlands of the Hulunbuir Grassland, China.

Climate warming generates a tremendous threat to the stability of geographically-isolated wetland (GIW) ecosystems and changes the type of evaporation and atmospheric precipitation in a region. The intrinsic balance of biogeochemical processes and enzyme activity in GIWs may be altered as well. In this paper, we sampled three types of GIWs exhibiting different kinds of flooding periods. With the participation of real-time temperature regulation measures, we assembled a computer-mediated wetland warming micro-system in June 2016 to simulate climate situation of ambient temperature (control group) and two experimental temperature differences (+2.5 °C and +5.0 °C) following a scientific climate change circumstance based on daily and monthly temperature monitoring at a two-minutes scale. Our results demonstrate that the contents of the total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) in the warmed showed, roughly, a balance or a slight decrease than the control treatment. Warming obstructed the natural subsidence of sediment, but reinforced the character of the ecological source, and reduced the activity of urease (URE), but promoted the activity of alkaline phosphatase (AKP) and sucrase (SUC). Redundancy analysis showed that sucrase, urease, available phosphorus (AP), and pH were the major correlating factors under warming conditions in our research scope. Total organic carbon, total nitrogen, sucrase, catalase (CAT), and alkaline phosphatase were the principal reference factors to reflect the ambient temperature variations. Nutrient compositions and enzyme activities in GIW ecosystems could be reconstructed under the warming influence.