Identification and functional analysis of non-coding regulatory small RNA FenSr3 in Bacillus amyloliquefaciens LPB-18.

Bacillus amyloliquefaciens is an interesting microbe in the food processing and manufacturing industries. Non-coding small RNAs (sRNAs) have been shown to play a crucial role in the physiology and metabolism of bacteria by post-transcriptionally regulating gene expression. This study investigated the function of novel sRNA FenSr3 by constructing fenSr3 deficient strain and complementary strains in B. amyloliquefaciens LPB-18 , which were named LPN-18N and LPB-18P, respectively. The result showed significant differences in fengycin yield between strain LPB -18N and LPB-18P. The production of fengycin was significantly enhanced in B. amyloliquefaciens LPB-18N, compared with that of the strain LPB-18 from 190.908 mg/L to 327.598 mg/L. Moreover, the production of fengycin decreased from 190.464 mg/L to 38.6 mg/L in B . amyloliquefaciens LPB-18P. A comparative transcriptome sequencing was carried out to better understand the complex regulatory mechanism. Transcription analysis revealed that 1037 genes were differentially expressed between B. amyloliquefaciens LPB-18 and B. amyloliquefaciens LPB-18N, including the key regulatory genes in fatty acid, amino acid biosynthesis, and central carbon metabolism, which could provide sufficient quantities of building precursors for fengycin biosynthesis. The biofilm formation and sporulation was also enhanced in the strain LPB-18N, which indicates that FenSr3 could play a vital role in stress resistance and promotes survival in B. amyloliquefaciens. Some sRNAs involved in stress response have been identified in the literature, but their regulatory roles in fengycin production remain unclear. The study will contribute a novel perspective to the regulation mechanism of biosynthesis and the optimization of key metabolites of B. amyloliquefaciens.

Beneficial Effects of Fermentation of Red Chili Pepper Using Lactococcus lactis subs. Cremoris RPG-HL-0136 in High-Fat Diet-Induced Obese Mice.

Red chili pepper is a beneficial natural spicy food that has antiobesity and antitype II diabetes effects, but it is not conducive to in-depth research as a dietary strategy to treat obesity. This study aims to investigate the beneficial effects of red chili pepper, fermented with a novel Lactococcus lactis subs. cremoris RPG-HL-0136. LC-MS/MS analysis is conducted to detect the content of capsaicin and dihydrocapsaicin, and no significant difference is observed between the nonfermented red chili pepper (NFP) (W/W) and the prepared L. lactis subs. cremoris RPG-HL-0136-fermented chili mixture (LFP). After establishing a high-fat diet-induced obese type II diabetic mouse model, the effects on weight gain, weight loss of liver and testicular fat, total cholesterol, triglyceride, fasting glucose, insulin, and homeostatic model assessment for insulin resistance in LFP were evaluated to be better than those in NFP following 10 weeks of interventions. All animal experiments were approved by the Institutional Animal Care and Use Committee of Xinxiang medical university. NFP and LFP could increase the expression of transient receptor potential vanilloid subfamily 1, peroxisome proliferator-activated receptor-alpha and caspase-2 in the high-fat mice. Compared with unfermented red chili pepper, the fermented red chili pepper complex significantly reduced LPS, tumor necrosis factor-alpha, and interleukin-6 in serum (P < .05). Intake of LFP significantly increased the expression of claudin-1 and occludin in the colon of the high-fat mice (P < .05), and there was no damage to the stomach and colon. This study provides scientific evidence that red chili pepper, fermented with L. lactis subs. cremoris RPG-HL-0136, may be beneficial for future treatment of obesity and accompanying diabetes. (IACUC.No.XYLL-20200019).

The Risk of Gastrointestinal Cancer on Daily Intake of Low-Dose BaP in C57BL/6 for 60 Days.

BACKGROUND: Benzo(a)pyrene (BaP) is a carcinogenic compound in contaminated foodstuffs. The effect of oral intake of the environmental carcinogen BaP under low doses and frequent exposure on a digestive system has not been thoroughly verified. METHODS: In this regard, this study was conducted to prove the toxicity effects of BaP on the stomach and colon tissue after exposure to C57BL/6 mouse (3 and 6 µg/kg) following daily oral administration for 60 days. This study investigated acute gastric mucosal injury, severe gastric edema, cell infiltration, and mononuclear cells, multifocal cells, and tumoral inflammatory cells. RESULTS: The results of ELISA showed that the expression of serum interleukin (IL)-6 and tumor necrosis factor-α in the BaP exposure group were significantly increased, and a high level of DNA adduct distribution in their stomach and colon. Moreover, this study has confirmed the expression of early carcinogenesis markers: nuclear factor (NF)-κB, p53, IL-6, superoxide dismutase 1 (SOD1), mucin (MUC1 and MUC2), and ß-catenin in the stomach and colon, and showed that there was a significant increase in IL-6, NF-κB, SOD1, ß-catenin, and MUC1 (P < 0.05). At the same time, there was a significant decrease in MUC2 and p53 (P < 0.05). Thus, even in low doses, oral intake of BaP can induce DNA damage, increasing the potential risk of gastrointestinal cancer. CONCLUSION: This study will provide a scientific basis for researching environmental contaminated food and intestinal health following daily oral administration of BaP.

Transcriptome Analysis of Bacillus amyloliquefaciens Reveals Fructose Addition Effects on Fengycin Synthesis.

Fengycin is a lipopeptide produced by Bacillus that has a strong inhibitory effect on filamentous fungi; however, its use is restricted due to poor production and low yield. Previous studies have shown that fengycin biosynthesis in B. amyloliquefaciens was found to be significantly increased after fructose addition. This study investigated the effect of fructose on fengycin production and its regulation mechanism in B. amyloliquefaciens by transcriptome sequencing. According to the RNA sequencing data, 458 genes were upregulated and 879 genes were downregulated. Transcriptome analysis results showed that fructose changed the transcription of amino acid synthesis, fatty acid metabolism, and energy metabolism; alterations in these metabolic pathways contribute to the synthesis of fengycin. In an MLF medium (modified Landy medium with fructose), the expression level of the fengycin operon was two-times higher than in an ML medium (modified Landy medium). After fructose was added to B. amyloliquefaciens, the fengycin-synthesis-associated genes were activated in the process of fengycin synthesis.

Privacy Protection for Telecare Medicine Information Systems Using a Chaotic Map-Based Three-Factor Authenticated Key Agreement Scheme.

Telecare medicine information systems (TMIS) provide flexible and convenient e-health care. However, the medical records transmitted in TMIS are exposed to unsecured public networks, so TMIS are more vulnerable to various types of security threats and attacks. To provide privacy protection for TMIS, a secure and efficient authenticated key agreement scheme is urgently needed to protect the sensitive medical data. Recently, Mishra et al. proposed a biometrics-based authenticated key agreement scheme for TMIS by using hash function and nonce, they claimed that their scheme could eliminate the security weaknesses of Yan et al.'s scheme and provide dynamic identity protection and user anonymity. In this paper, however, we demonstrate that Mishra et al.'s scheme suffers from replay attacks, man-in-the-middle attacks and fails to provide perfect forward secrecy. To overcome the weaknesses of Mishra et al.'s scheme, we then propose a three-factor authenticated key agreement scheme to enable the patient to enjoy the remote healthcare services via TMIS with privacy protection. The chaotic map-based cryptography is employed in the proposed scheme to achieve a delicate balance of security and performance. Security analysis demonstrates that the proposed scheme resists various attacks and provides several attractive security properties. Performance evaluation shows that the proposed scheme increases efficiency in comparison with other related schemes.

Robust ECC-based authenticated key agreement scheme with privacy protection for Telecare medicine information systems.

To protect the transmission of the sensitive medical data, a secure and efficient authenticated key agreement scheme should be deployed when the healthcare delivery session is established via Telecare Medicine Information Systems (TMIS) over the unsecure public network. Recently, Islam and Khan proposed an authenticated key agreement scheme using elliptic curve cryptography for TMIS. They claimed that their proposed scheme is provably secure against various attacks in random oracle model and enjoys some good properties such as user anonymity. In this paper, however, we point out that any legal but malicious patient can reveal other user's identity. Consequently, their scheme suffers from server spoofing attack and off-line password guessing attack. Moreover, if the malicious patient performs the same time of the registration as other users, she can further launch the impersonation attack, man-in-the-middle attack, modification attack, replay attack, and strong replay attack successfully. To eliminate these weaknesses, we propose an improved ECC-based authenticated key agreement scheme. Security analysis demonstrates that the proposed scheme can resist various attacks and enables the patient to enjoy the remote healthcare services with privacy protection. Through the performance evaluation, we show that the proposed scheme achieves a desired balance between security and performance in comparisons with other related schemes.

[Study on the chemical constituents of Dichrocephala integrifolia].

OBJECTIVE: To study chemical constituents of Dichrocephala integrifolia (L.) O. Kuntze. METHODS: The constituents were isolated and purified by silica gel column and Sephadex LH-20 chromatography. Their structures were elucidated by spectral analysis and physicochemical properties. RESULTS: Six compounds were obtained and identified as stearic acid (1), stigmasta-7,22-dien-3-ol (2), alpha-amyrin (3), epifriedelanol (4), Methyl stearate (5) and tritetracontane (6). CONCLUSION: All these compounds are obtained from this plant for the first time.