INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
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2016
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IF 3.445
Faizan A. Sadiq,Yun Li,TongJie Liu,Steve Flint,Guohua Zhang,Lei Yuan,Zhipeng Pei,GuoQing He
The propensity for aerobic bacilli and allied genera to produce highly heat-resistant spores and thermally stable spoilage enzymes are major bacteriological issues faced by the dairy industry. Most of the enzymes are able to survive any heat treatment applied during the manufacture of milk powders and have the potential to remain active in milk powders and other dairy products during storage, and may explain some of the sensory and functionality defects reported in dairy products . Despite many reports on the occurrence of spore-forming bacteria in dairy products, knowledge about food quality related properties of many aerobic sporeformers is still scarce. Therefore, the aim of this study was to determine thermal resistance and spoilage potential of a large pool of mesophilic and thermophilic sporeformers, representing 738 isolates and 31 different RAPD groups, recently isolated from Chinese milk powders. Spore formers producing highly heat resistant spores (surviving 125 °C for 30 min) included 2 thermophiles ( Geobacillus thermoleovorans group and Geobacillus stearothermophilus ) and one mesophilic species ( Brevibacillus brevis ). Paenibacillus macerans showed the highest proteolytic activity followed by members of the Bacillus cereus group, Br. brevis , Bacillus subtilis , G. thermoleovorans group and Virgibacillus proomii . The highest lipase producing strains belonged to Bacillus licheniformis . Phospholipase activity was only shown by members of the B. cereus group and Brevibacillus parabrevis . Ten strains showed positive β -galactosidase activity, while, 4 strains showed positive haemolytic activity. B. licheniformis strains, despite belonging to one RAPD group or sub-group showed markedly different phenotypic characters which support the previous findings of heterogeneity in RAPD-based B. licheniformis groups. The results of this study will broaden the knowledge about the spoilage potential and thermal resistance of many strains of dairy origin.
研究领域:
食品科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DAIRY SCIENCE
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2019
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IF 3.082
Kejin Zhuang,Hongfu Li,Ziwei Zhang,Shuang Wu,Yashuo Zhang,Edward M. Fox,Chaoxin Man,Yujun Jiang
ABSTRACT Bacillus cereus sensu lato is one of the most harmful bacterial groups affecting the quality and safety of powdered infant formula (PIF). In this study, samples were collected from the raw materials and processing environments of PIF. A total of 84 isolates were identified as Bacillus cereus sensu stricto ( B. cereus s. s. ) by 16S rRNA analysis, molecular typing technology, and physiological and biochemical tests. The 84 B. cereus s. s. strains were assigned to panC group II, group III, and group IV. Then, the 7 housekeeping genes glpF , gmk , ilvD , pta , pur , pycA , and tpi were selected for multilocus sequence typing. Results showed that the 84 isolates were clustered into 24 sequence types (ST), and 14 novel ST were detected. Among the 24 ST, ST999 (19/84, 22.62%) and ST1343 (13/84, 15.48%) predominated. The correlation between processing areas and ST showed that the processing environments of the production and packing areas were the most susceptible to contamination by B. cereus s. s . Spores of these ST showed different heat resistance phenotypes evaluated by the analysis of D T (time in minutes of spore decimal reduction at each temperature) and Z values (temperature increase required to reduce the D T value to one-tenth of the original). Spores from group III according to panC gene analysis were the most heat resistant. These findings will help us to better understand B. cereus s. s. contamination and control in PIF processing environments.
研究领域:
微生物学
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食品安全
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
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2021
·Vol. 19
·期 1
·1-14
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IF 10.435
Guo Xiaoyang,Liu Jia,Jiang Lingdong,Gong Wanjun,Wu Huixia,He Qianjun
Background Photothermal therapy (PTT) frequently cause thermal resistance in tumor cells by inducing the heat shock response, limiting its therapeutic effect. Hydrogen sulfide (H2S) with appropriate concentration can reverse the Warburg effect in cancer cells. The combination of PTT with H2S gas therapy is expected to achieve synergistic tumor treatment.Methods Here, sulourea (Su) is developed as a thermosensitive/hydrolysable H2S donor to be loaded into Pd nanocubes through in-depth coordination for construction of the Pd-Su nanomedicine for the first time to achieve photo-controlled H2S release, realizing the effective combination of photothermal therapy and H2S gas therapy.Results The Pd-Su nanomedicine shows a high Su loading capacity (85 mg g−1), a high near-infrared (NIR) photothermal conversion efficiency (69.4%), and NIR-controlled H2S release by the photothermal-triggered hydrolysis of Su. The combination of photothermal heating and H2S produces a strong synergetic effect by H2S-induced inhibition of heat shock response, thereby effectively inhibiting tumor growth. Moreover, high intratumoral accumulation of the Pd-Su nanomedicine after intravenous injection also enables photothermal/photoacoustic dual-mode imaging-guided tumor treatment.Conclusion sThe proposed NIR-responsive heat/H2S release strategy provides a new approach for effective cancer therapy.Graphic abstract
研究领域:
纳米技术
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癌症治疗
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光热治疗
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气体治疗
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
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2024
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IF 13
Bingshuai Zhou,Biao Dong,Songtao Hu,Wei Liu,Liheng Sun,Lin Xu,Xue Bai,Lin Wang,Manlin Qi,Hongwei Song
Photothermal treatment (PTT) has emerged as a promising avenue for biofilm elimination, yet its potential drawbacks, such as local hyperpyrexia and bacterial heat resistance, have posed challenges. To address these concerns, an innovative nanoplatform (Au@mSiO 2 -arg/ICG) is devised that integrates phototherapeutic and gas therapeutic functionalities. This multifaceted nanoplatform is composed of mesoporous silica-coated Au nanorods (Au@mSiO 2 ), supplemented with l -arginine ( l -arg) and indocyanine green (ICG), and is engineered for mild temperature PTT aimed at biofilm eradication. Au@mSiO 2 -arg/ICG nanoparticles (NPs) show excellent antibacterial effects through the generation of nitric oxide (NO) gas, heat, and reactive oxygen species (ROS) under 808 nm light irradiation. The ROS generated by ICG initiates a cascade reaction with l -arg, ultimately yielding NO gas molecules. This localized release of NO not only effectively curbs the expression of heat shock proteins 70 mitigating bacterial thermoresistance, but also reduces extracellular polymeric substance allowing better penetration of the therapeutic agents. Furthermore, this nanoplatform achieves an outstanding biofilm elimination rate of over 99% in an abscess model under 808 nm light irradiation (0.8 W·cm −2 ), thereby establishing its potential as a dependable strategy for NO-enhanced mild PTT and antibacterial photodynamic therapy (aPDT) in clinical settings.
研究领域:
纳米技术
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生物医学工程
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药学
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微生物学
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治疗学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Acta Biomaterialia
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2022
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IF 10.633
Yaping Shen,Yang Zou,Binglin Bie,Chanjuan Dong,Yonggang Lv
Although mild photothermal therapy (mild-PTT) avoids treatment bottleneck of the traditional PTT, the application of mild-PTT in deep and internal tumors is severely restricted due to thermal resistance, limited irradiation area and penetration depth. In addition, bone resorption caused by tumor colonization in distal bone tissue exacerbates tumor progression. Here, a strategy was developed for the treatment of bone metastasis and alleviation of bone resorption, which was based on liquid metal (LM) nanoparticle to resist thermal resistance induced by mild-PTT via autophagy activation. Briefly, LM and autophagy activator (Curcumin, Cur) were loaded into zeolitic imidazolate framework-8 (ZIF-8), which was then functionalized with hyaluronic acid/alendronate (CLALN). CLALN exhibited good photothermal performance, drug release ability under acidic environment, specifical recognition and aggregation at bone metastasis sites. CLALN combined with mild-PPT dramatically inhibited tumor progress by inducing the impaired autophagy and reduced the expression of programmed cell death ligand 1 (PD-L1) protein triggered by mild-PTT, resisting thermal resistance and alleviating the immunosuppression. Besides, CLALN combined with mild-PPT effectively alleviated osteolysis compared with only CLALN or mild-PPT. Our experiments demonstrated that this multi-functional LM-based nanoparticle combined with autophagy activation provided a promising therapeutic strategy for bone metastasis treatment. Statement of significance Due to the limited light penetration, photothermal therapy (PTT) has limited inhibitory effect on tumor cells colonized in the bone. In addition, nonspecific heat diffusion of PTT may accidentally burn normal tissues and damage peripheral blood vessels, which can block the accumulation of drugs in deep tumors. Here, a multifunctional liquid metal based mild-PTT delivery system is designed to inhibit tumor growth and bone resorption by modulating the bone microenvironment and activating autophagy “on demand”. It can overcome the treatment bottleneck of traditional PTT and improve the treatment effect of mild-PTT by resisting photothermal resistance and immune suppression. In addition, it also exhibits favorable heat/acid-responsive drug release performance and can specifically target tumor cells at the site of bone metastases.
研究领域:
癌症治疗
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纳米技术
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生物医学工程
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药学
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光热疗法
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骨转移
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）