The medicinal plant Glehnia littoralis has become increasingly endangered in China.To assist in the formulation of conservation strategies for this species, we assessed the genetic diversity of G. littoralis with a total of 172 samples from 10 populations using SRAP markers. The results showed that Nei's gene diversity (H) per locus ranged from 0.04 to 0.2504, with an average of 0.245, and that Shannon's information index (I) ranged from 0.233 to 0.6253, averaging 0.5516 at the population level. The total genetic diversity (Ht) was 0.2471, and 66.5% (Hs=0.1643) of the total genetic variation was attributed to within-population diversity (P <0.05), with the rest (33.5%) due to differences between populations (Gst=0.3353), indicating that gene flow was restricted among populations (Nm=0.9911). AMOVA also suggested that the main source of variation was within populations (77.8%), whereas 22.2% of differentiation was found among populations. Estimates of genetic distance were not correlated with geographic distance according to a Mantel test (r = 0.0792, P = 0.329). These results show that high levels of genetic variation are present within and among populations.The endangered status of this species is likely due to the destruction of the habitats of the wild populations, rather than a loss of genetic diversity.

Recently, the highly efficient production of value-added biobased chemicals from available, inexpensive, and renewable biomass has gained more and more attention in a sustainable catalytic process. Furfural is a versatile biobased chemical, which has been widely used for making solvents, lubricants, inks, adhesives, antacids, polymers, plastics, fuels, fragrances, flavors, fungicides, fertilizers, nematicides, agrochemicals, and pharmaceuticals. In this work, ultrasonic-treated chestnut shell waste (UTS-CSW) was utilized as biobased support to prepare biomass-based heterogeneous catalyst (CSUTS-CSW) for transforming waste lignocellulosic materials into furfural. The pore and surface properties of CSUTS-CSW were characterized with BET, SEM, XRD, and FT-IR. In toluene–water (2:1, v:v; pH 1.0), CSUTS-CSW (3.6 wt%) converted corncob into furfural yield in the yield of 68.7% at 180 °C in 15 min. CSUTS-CSW had high activity and thermostability, which could be recycled and reused for seven batches. From first to seventh, the yields were obtained from 68.7 to 47.5%. Clearly, this biobased solid acid CSUTS-CSW could be used for the sustainable conversion of waste biomasses into furfural, which had potential application in future.

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Avermectin B 1a batch fermentation of Streptomyces avermitilis in a 2 m 3 fermentor was investigated by oxygen uptake rate (OUR) regulation during cell growth phase. OUR was controlled by adjusting of aeration and agitation. Result showed that OUR strongly affected cell growth and antibiotics production. Avermectin B 1a biosynthesis could be effectively enhanced when OUR was stably regulated at an appropriate level in batch fermentation of S. avermitilis. Avermectin B 1a yield reached 5568 ± 111 mg/l by controlling maximal OUR between 15 and 20 mmol/l/h during cell growth phase, which was increased by 21.8% compared with the control (maximal OUR above 20 mmol/l/h). The stimulation effect on avermectin B 1a production could be attributed to the improved supply of propionic acid and acetic acid, the precursors of avermectin B 1a , in the cells. Hence, this OUR control method during cell growth phase may be a simple and applicable way to improve industrial production of avermectin.

Background: Plant chloroplast DNA (cpDNA) typically has a circular structure, including a large single-copy region (LSC), a small single-copy region (SSC) and two inverted repeats (IR1 and IR2). The organization of these four elementary regions LSC-IR1-SSC-IR2 is highly conserved across all plant cpDNAs. Only very a few structural variations (SVs) occurring at the elementary-region level have been reported. Results: In the present study, we assembled the full-length cpDNA of Dongxiang wild rice line 159 (DXWR159). Using the long PacBio subreads, we discovered a large inversion of SSC and a large duplication of IR in DXWR159 cpDNAs. The large inversion of SSC results in a reverse orientation of SSC. According to the orientation of SSC, the structures of cpDNAs can be classified into the forward SSC (SSC-F) and reverse SSC (SSC-R) types. As the most significant finding, both SSC-R and SSC-F type cpDNAs were detected in several seedlings of DXWR159 with a ratio of 1.2. The frequent inversion of SSC was named as SSC switching.Conclusions: The frequencies of Short tandem repeats (STRs) and large SVs in plant cpDNAs need to be intensely investigated for rediscovery. STRs may not be useful as molecular markers in phylogenetic studies, particularly at low taxonomic levels. We propose that: (1) SSC switching ubiquitous occurs in plant cpDNAs and is not a rarely occurring event; (2) SSC switching may be active or inactive by regulation at the molecular level; and (3) further investigation of the underlying mechanism may reveal novel and important functions associated with SSC switching.