Artificial neural network-genetic algorithm-based optimization of aerobic composting process parameters of Ganoderma lucidum residue.

The rapid development of traditional Chinese medicine enterprises has put forward higher requirements for the resource utilization of traditional Chinese medicine residues (TCMR). Aerobic composting of TCMR to prepare bio-organic fertilizer is an effective resource utilization method. In this study, a back-propagation artificial neural network (BPNN) model using composting factors as inputs (C/N, initial moisture content, type of inoculant, composting days) and the humic acid content as the output was constructed based on the orthogonal test data. BPNN-GA (a genetic algorithm) was used for extreme value optimization, and the optimal composting process parameter combination was obtained and verified. The results show that the combination of orthogonal testing and BPNN can effectively establish the relationship between the composting process parameters and humic acid content. The R2 value was 0. 9064. The optimized parameter combination is as follows: C/N,37.42; moisture content,69.76%; bacteria,no; and composting time,50 d.

Bioaugmentation improves the anaerobic co-digestion of cadmium-containing plant residues and cow manure.

Phytoremediation causes a large quantity of phytoremediation residues rich in heavy metals (HMs). This kind of plant residue can be used as a substrate for anaerobic digestion (AD) to reduce the content of HM-containing biomass, but high concentrations of HMs will inhibit the digestion efficiency and reduce the conversion efficiency of plant residues. Bioaugmentation may be an effective method to improve the degradation efficiency and methane yield of plant residues rich in HMs. In this study, a cellulose-degrading anaerobic bacteria Paracoccus sp. Termed strain LZ-G1 was isolated from cow dung, which can degrade cellulose and simultaneously adsorb Cd2+. The Cd2+ (10 mg/L)-adsorbtion efficiency and cellulose (463.12 g/kg)-degradation rate were 65.1 % and 60.59 %, respectively. In addition, using the strain LZ-G1 bioaugmented Cd2+-containing plant residues and cow manure mixed AD system, the system's biogas and methane production significantly increased (98.97 % and 142.03 %, respectively). During the AD process, the strain LZ-G1 was successfully colonized in the digestion system. Furthermore, the microbial community analysis revealed that LZ-G1 bioaugmentation alleviates the toxicity of free Cd2+ to the microbial community in the AD system, regulates and restores the archaea genus dominant in the methanogenesis stage, and restores the relative abundance of dominant bacteria associated with biomass hydrolysis. The restoration of the microbial community increased the biogas yield and methane production rate. Thus, bioaugmentation provides an easy and a feasible method for the actual on-site treatment of HM-rich phytoremediation residues.

The phyllosphere indigenous microbiota of Brassica campestris L. change its diversity in responding to di-n-butyl phthalate pollution.

In this study, the effects of di-n-butyl phthalate (DBP) on the phyllosphere bacterial community of field mustard (Brassica campestris L.) at the five-leaf stage were investigated. The indigenous alpha-diversity of the phyllosphere bacteria was altered after spraying with different concentrations of DBP. Shannon diversity indices were significantly changed on day 5 after treatment at DBP concentrations > 400 mg L-1 (P > 0.05). Nevertheless, the difference between treatment and control was not significant on day 9 after DBP treatment (P > 0.05). Exposure to DBP resulted in a decrease in Proteobacteria and Firmicutes, and an increase in Actinobacteria at all sampling intervals. These changes included significant increases in the relative abundance of Paracoccus and Rhodococcus, and significant decreases in that of Pseudomonas, Exiguobacterium, an unclassified genus of Pseudomonadaceae, and an unclassified genus of Enterobacteriaceae. This study provides new evidence for the possibility of using phyllosphere microbiota to remediate DBP contamination.

Fast simultaneous determination of main components and impurity sodium ion in PAMA injection by mixed-mode chromatography.

This study describes an analytical method to control the quality of potassium aspartate and magnesium aspartate (PAMA) injection based on the simultaneous detection of the main components (K+, Mg2+ and Asp) and impurities (Na+) using a mixed-mode chromatography coupled with charged aerosol detector. To obtain optimal chromatographic separation, the effects of organic content, column temperature, buffer types, pH and concentrations were evaluated. A Response Surface Methodology (RSM) optimal design was performed after single factor experiment. The mixed-mode HPLC method is proved to be a complementary approach to the conventional ion chromatography (IC). The optimized method was successfully validated and applied to the analysis of Asp, K+, Na+ and Mg2+ in PAMA injection with good specificity, linearity, accuracy, and repeatability. The method would be useful for quality control in PAMA injection and other similar drugs, which can provide references for the analysis of drug quality by enterprises and drug regulatory department.

Seasonal changes in the vertical distribution of two types of multicellular magnetotactic prokaryotes in the sediment of Lake Yuehu, China.

There are two genetically distinct morphological types of multicellular magnetotactic prokaryotes (MMPs) in the intertidal zone of Lake Yuehu (China): ellipsoidal MMPs (eMMPs) and spherical MMPs (sMMPs). We studied the vertical distribution of both types of MMPs in the sediment at Lake Yuehu during 1 year. Both types of MMPs were observed at sediment depths ranging from 1 to 34 cm, depending on the seasons. The eMMPs distributed at depths of 2-34 cm during spring, 1-11 cm during summer, 2-21 cm during autumn and 9-32 cm during winter. The eMMP species Candidatus Magnetananas rongchenensis, with magnetite magnetosomes, dominated at all distribution depths. These results suggested that Ca. M. rongchenensis migrated vertically during four seasons. The vertical profiles of oxidation-reduction potential (ORP) in Lake Yuehu changed seasonally, and these changes coincided with the seasonal distribution of MMPs, suggesting that the ORP affected the vertical distribution of MMPs. In addition, high concentrations of ammonium and silicate were associated with low abundances of MMPs.

A review on the applications of microbial electrolysis cells in anaerobic digestion.

Anaerobic digestion (AD) has been widely used for biogas or biofuel generation from waste treatment. Because a low production rate and instability of AD occur frequently, various technologies have been applied to improvement of AD. Microbial electrolysis cells (MECs), an emerging technology, can convert organic matter into hydrogen, methane, and other value-added products. Recent studies showed that application of MEC to AD (MEC-AD) can accelerate degradation of a substrate (including recalcitrant compounds) and alter AD microbial community by enriching exoelectrogens and methanogens thus increasing biogas production. With stable microbial communities established, improvement of MEC-AD for methane production was achieved. MEC-AD process can be monitored in real-time by detecting electric signals, which linearly correlate with substrate concentrations. This review attempts to evaluate interactions among the decomposition of substrates, MEC-AD system, and the microbial community. This analysis should provide useful insights into the improvement of methane production and the performance of MEC-AD.

Identification and characterization of lymph organ microRNAs in red swamp crayfish, Procambarus clarkii infected with white spot syndrome virus.

MicroRNAs (miRNAs) were important post-transcriptional regulators and played vital roles in innate immunity system of invertebrates, especially in the aspect of antivirus. In this study, using high-throughput small RNAs Illumina sequencing system, differentially expressed miRNAs (DEMs) from lymph organs in red swamp crayfish, Procambarus clarkii, infected with white spot syndrome virus, were identified. As a result, 32 known miRNAs and 7 novel miRNAs were identified in crayfish lymph organ small RNAs library of NG and WG. Among them, 7 differentially expressed miRNAs (DEMs) were predicted to be involved in the lymph organ antiviral innate immunity of P. clarkii. Besides, the results showed that putative target genes of these DEMs were related with tight junction, RNA transport, regulation of actin cytoskeleton, focal adhesion, vascular smooth muscle contraction, mRNA surveillance pathway, NOD-like receptor signaling pathway, leukocyte transendothelial migration, and protein processing in endoplasmic reticulum. These results might provide the guiding theoretical foundation for future studies about crustaceans' antiviral innate immunity.

Archaea Dominate the Ammonia-Oxidizing Community in Deep-Sea Sediments of the Eastern Indian Ocean-from the Equator to the Bay of Bengal.

Ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) oxidize ammonia to nitrite, and therefore play essential roles in nitrification and global nitrogen cycling. To better understand the population structure and the distribution of AOA and AOB in the deep Eastern Indian Ocean (EIO), nine surface sediment samples (>3,300 m depth) were collected during the inter-monsoon Spring 2013. One sediment sample from the South China Sea (SCS; 2,510 m) was also included for comparison. The community composition, species richness, and diversity were characterized by clone libraries (total 1,238 clones), and higher diversity of archaeal amoA genes than bacterial amoA genes was observed in all analyzed samples. Real time qPCR analysis also demonstrated higher abundances (gene copy numbers) of archaeal amoA genes than bacterial amoA genes, and the ratios of AOA/AOB ranged from 1.42 to 8.49 among sites. In addition, unique and distinct clades were found in both reconstructed AOA and AOB phylogeny, suggesting the presence of niche-specific ammonia-oxidizing microorganisms in the EIO. The distribution pattern of both archaeal and bacterial amoA genes revealed by NMDS (non-metric multidimensional scaling) showed a distinct geographic separation of the sample from the SCS and most of the samples from the EIO following nitrogen gradients. Higher abundance and diversity of archaeal amoA genes indicated that AOA may play a more important role than AOB in the deep Indian Ocean. Environmental parameters shaping the distribution pattern of AOA were different from that of AOB, indicating distinct metabolic characteristics and/or adaptation mechanisms between AOA and AOB in the EIO, especially in deep-sea environments.

Analysis of gene gain and loss in the evolution of predatory bacteria.

Predatory bacteria are ubiquitously distributed in nature in including in aquatic environments, sewage, intestinal tracts of animals and humans, rhizophere and, soils. However, our understanding of their evolutionary history is limited. Results of recent studies have shown that acquiring novel genes is a major force driving bacterial evolution. Therefore, to gain a better understanding of the impact of gene gain and loss in the evolution of bacterial predators, this study employed comparative genomic approaches to identify core-set gene families and species-specific gene families, and model gene gain and loss events among 11 genomes that represented diverse lineages. In total, 1977 gene families were classified. Of these 509 (pattern 11111111111) were present all of the 11 species. Among the non-core set gene families, 52 were present only in saltwater bacteria predators and had no ortholog in the other genomes. Similarly 109 and 44 were present only in the genomes of Micavibrio spp. and Bdellovibrio spp., respectively. In this study, the gain loss mapping engine GLOOME was selected to analyze and estimate the expectations and probabilities of both gain and loss events in the predatory bacteria. In total, 354 gene families were involved in significant gene gain events, and 407 gene families were classified into gene loss events with high supported value. Moreover, 18 families from the core set gene family were identified as putative genes under positive selection. The results of this study suggest that acquisition of particular genes that encode functional proteins in metabolism and cellular processes and signaling, especially ABC systems, may help bacterial predators adapt to surrounding environmental changes and present different predation strategies for survival in their habitats.