Cellulolytic Bacillus cereus produces a variety of short-chain fatty acids and has potential as a probiotic.

Cellulolytic bacteria ferment dietary fiber into short-chain fatty acids, which play an important role in improving fiber utilization and maintaining intestinal health. Safe and effective cellulolytic bacteria are highly promising probiotic candidates. In this study, we isolated three strains of Bacillus cereus, which exhibited cellulolytic properties, from Kele pig feces. To assess the genetic basis of cellulose degradation by the isolates, whole-genome sequencing was used to detect functional genes associated with cellulose metabolism. Subsequently, we identified that the B. cereus CL2 strain was safe in mice by monitoring body weight changes, performing histopathologic evaluations, and determining routine blood indices. We next evaluated the biological characteristics of the CL2 strain in terms of its growth, tolerance, and antibiotic susceptibility, with a focus on its ability to produce short-chain fatty acids. Finally, the intestinal flora structure of the experimental animals was analyzed to assess the intestinal environment compatibility of the CL2 strain. In this study, we isolated a cellulolytic B. cereus CL2, which has multiple cellulolytic functional genes and favorable biological characteristics, from the feces of Kele pigs. Moreover, CL2 could produce a variety of short-chain fatty acids and does not significantly affect the diversity of the intestinal flora. In summary, the cellulolytic bacterium B. cereus CL2 is a promising strain for use as a commercial probiotic or in feed supplement. IMPORTANCE: Short-chain fatty acids are crucial constituents of the intestinal tract, playing an important and beneficial role in preserving the functional integrity of the intestinal barrier and modulating both immune responses and the structure of the intestinal flora. In the intestine, short-chain fatty acids are mainly produced by bacterial fermentation of cellulose. Therefore, we believe that safe and efficient cellulolytic bacteria have the potential to be novel probiotics. In this study, we systematically evaluated the safety and biological characteristics of the cellulolytic bacterium B. cereus CL2 and provide evidence for its use as a probiotic.

Polyphonic sound event localization and detection based on Multiple Attention Fusion ResNet.

Sound event localization and detection have been applied in various fields. Due to the polyphony and noise interference, it becomes challenging to accurately predict the sound event and their occurrence locations. Aiming at this problem, we propose a Multiple Attention Fusion ResNet, which uses ResNet34 as the base network. Given the situation that the sound duration is not fixed, and there are multiple polyphonic and noise, we introduce the Gated Channel Transform to enhance the residual basic block. This enables the model to capture contextual information, evaluate channel weights, and reduce the interference caused by polyphony and noise. Furthermore, Split Attention is introduced to the model for capturing cross-channel information, which enhances the ability to distinguish the polyphony. Finally, Coordinate Attention is introduced to the model so that the model can focus on both the channel information and spatial location information of sound events. Experiments were conducted on two different datasets, TAU-NIGENS Spatial Sound Events 2020, and TAU-NIGENS Spatial Sound Events 2021. The results demonstrate that the proposed model significantly outperforms state-of-the-art methods under multiple polyphonic and noise-directional interference environments and it achieves competitive performance under a single polyphonic environment.

Effect of feeding fermented distiller's grains diets on immune status and metabolomics of spleen and mesenteric lymph nodes in finishing cattle.

To explore the effect of feeding fermented distiller's grains (FDG) diets on spleen and mesenteric lymph nodes (MLN) immune status and metabolomics in finishing cattle, eighteen Guanling crossbred cattle (18 months old, 250.0 ± 25 kg) were randomly divided into 3 groups: a basal diet (Control) group, an FDG-15% group, and an FDG-30% group (containing 0%, 15% and 30% FDG to partially replace the concentrates, respectively). After 75 days, the spleens and MLN were collected for detection of relative spleen weight, immune parameters, and metabolomic analysis. Compared with the Control group, FDG-30% group significantly increased (P<0.05) the relative spleen weight. In addition, the level of IL-17A in the spleen of the FDG-30% group was significantly higher than that of the FDG-15% group. Metabolomic analysis showed that differential metabolites (VIP＞1, P＜0.05) of spleen and MLN in FDG-15% and FDG-30% groups are mostly lipids and lipid molecules. KEGG analysis illustrated that choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance were metabolic pathways in spleen shared by FDG-15% group vs.Control group and FDG-30% group vs.Control group, and choline metabolism in cancer was a metabolic pathway in MLN shared by FDG-15% group vs.Control group and FDG-30% group vs.Control group. These results suggest that feeding FDG may promote spleen development by regulating choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance. Additionally, it may affect MLN development by regulating choline metabolism in cancer. SIGNIFICANCE: Fermented distiller's grains (FDG) is a high quality alternative to feed because it is rich in beneficial microorganisms and nutrients. The spleen and mesenteric lymph nodes (MLN) are important peripheral immune organs in animals, whose status reflects the health of the animal. However, there are few reports on the effect of feeding FDG diets on spleen and MLN immune status and metabolomics in domestic animals. In this study, we found that feeding FDG may promote spleen development by regulating choline metabolism in cancer, glycerophospholipid metabolism, biosynthesis of unsaturated fatty acids and insulin resistance metabolic pathways, and may affect MLN development by regulating choline metabolism in cancer. This study extends our understanding of the metabolomics of the spleen and MLN in FDG and helps to further understand of the immunomodulatory effects of the FDG diet.

Probiotic-Fermented Distillers Grain Alters the Rumen Microbiome, Metabolome, and Enzyme Activity, Enhancing the Immune Status of Finishing Cattle.

A total of 30 Simmental crossbred cattle (6.50 months old, 265.0 ± 22.48 kg) were randomly divided into three groups, with 10 heads per group, and fed for 45 days. The diet treatments consisted of the Control group without PFDG supplementation, the PFDG-15% group with 15% PFDG substituting for 15% concentrate, and PFDG-30% group with 30% PFDG substituting for 30% concentrate. The results showed that compared with the Control group, the average daily gain (ADG) of the cattle in the PFDG-30% group decreased significantly (0.890 vs. 0.768 kg/d, p = 0.005). The serum malondialdehyde content of cattle in the PFDG-15% and PFDG-30% groups decreased significantly (p = 0.047) compared to that of the Control group. However, the serum superoxide dismutase activity of cattle in the PFDG-30% group was significantly higher than that of the Control group (p = 0.047). Meanwhile, both the PFDG-15% and PFDG-30% groups (1758.47 vs. 2061.30 µg/mL) showed higher serum levels of immunoglobulin G, while the interleukin-10 concentration was lower in the PFDG-30% group (p = 0.027). In addition, the PFDG-15% and PFDG-30% groups shifted the rumen microbiota by improving the abundances of F082 (related to propionic acid production) and fiber-degrading bacteria (Lachnospiraceae_UGG-009 and Prevotellaceae_UCG-001) and reducing the abundance of the disease-associated bacteria Selenomonas. A Kyoto encyclopedia of genes and genomes (KEGG) analysis illustrated that three key metabolic pathways, including phenylalanine metabolism, pyrimidine metabolism, and tryptophan metabolism, were enriched in the PFDG-15% group, but eight key metabolic pathways, including arachidonic acid metabolism, were enriched in the PFDG-30% group. Importantly, both the PFDG-15% and PFDG-30% groups increased (p < 0.01) the activities of cellulase, lipase, and protease in the rumen. Finally, the different bacterial abundance in the rumen was associated with changes in the ADG, serum antioxidant capacity, immune status, rumen enzyme activity, and metabolites. These results suggest that PFDG alters rumen microbiome abundance, metabolome, and enzyme activity for enhancing serum antioxidant capacity and the immune status, but when the supplemental level reaches 30%, it has a negative effect on ADG and the anti-inflammatory factors in finishing cattle.

A Multi-Source Weighted Deep Transfer Network for Open-Set Fault Diagnosis of Rotary Machinery.

In real industries, there often exist application scenarios where the target domain holds fault categories never observed in the source domain, which is an open-set domain adaptation (DA) diagnosis issue. Existing DA diagnosis methods under the assumption of sharing identical label space across domains fail to work. What is more, labeled samples can be collected from different sources, where multisource information fusion is rarely considered. To handle this issue, a multisource open-set DA diagnosis approach is developed. Specifically, multisource domain data of different operation conditions sharing partial classes are adopted to take advantage of fault information. Then, an open-set DA network is constructed to mitigate the domain gap across domains. Finally, a weighting learning strategy is introduced to adaptively weigh the importance on feature distribution alignment between known class and unknown class samples. Extensive experiments suggest that the proposed approach can substantially boost the performance of open-set diagnosis issues and outperform existing diagnosis approaches.