Role of the hydrogen sulfide-releasing donor ADT-OH in the regulation of mammal neural precursor cells.

Neural precursor cells (NPCs) generate new neurons to supplement neuronal loss as well as to repair damaged neural circuits. Therefore, NPCs have potential applications in a variety of neurological diseases, such as spinal cord injury, traumatic brain injury, and glaucoma. Specifically, improving NPCs proliferation and manipulating their differentiated cell types can be a beneficial therapy for a variety of these diseases. ADT-OH is a slow-releasing organic H2 S donor that produces a slow and continuous release of H2 S to maintain normal brain functions. In this study, we aimed to explore the effect of ADT-OH on NPCs. Our results demonstrated that ADT-OH promotes self-renewal and antiapoptosis ability of cultured NPCs. Additionally, it facilitates more NPCs to differentiate into neurons and oligodendrocytes, while inhibiting their differentiation into astrocytes. Furthermore, it enhances axonal growth. Moreover, we discovered that the mRNA and protein expression of ß-catenin, TCF7L2, c-Myc, Ngn1, and Ngn2, which are key genes that regulate NPCs self-renewal and differentiation, were increased in the presence of ADT-OH. Altogether, these results indicate that ADT-OH may be a promising drug to regulate the neurogenesis of NPCs, and needs to be studied in the future for clinical application potential.

Absence of TRIM32 Leads to Reduced GABAergic Interneuron Generation and Autism-like Behaviors in Mice via Suppressing mTOR Signaling.

Mammalian target of rapamycin (mTOR) signaling plays essential roles in brain development. Hyperactive mTOR is an essential pathological mechanism in autism spectrum disorder (ASD). Here, we show that tripartite motif protein 32 (TRIM32), as a maintainer of mTOR activity through promoting the proteasomal degradation of G protein signaling protein 10 (RGS10), regulates the proliferation of medial/lateral ganglionic eminence (M/LGE) progenitors. Deficiency of TRIM32 results in an impaired generation of GABAergic interneurons and autism-like behaviors in mice, concomitant with an elevated autophagy, which can be rescued by treatment embryonically with 3BDO, an mTOR activator. Transplantation of M/LGE progenitors or treatment postnatally with clonazepam, an agonist of the GABAA receptor, rescues the hyperexcitability and the autistic behaviors of TRIM32-/- mice, indicating a causal contribution of GABAergic disinhibition. Thus, the present study suggests a novel mechanism for ASD etiology in that TRIM32 deficiency-caused hypoactive mTOR, which is linked to an elevated autophagy, leads to autism-like behaviors via impairing generation of GABAergic interneurons. TRIM32-/- mouse is a novel autism model mouse.

Verbascoside inhibits progression of glioblastoma cells by promoting Let-7g-5p and down-regulating HMGA2 via Wnt/beta-catenin signalling blockade.

Glioblastoma (GBM) continues to show a poor prognosis despite advances in diagnostic and therapeutic approaches. The discovery of reliable prognostic indicators may significantly improve treatment outcome of GBM. In this study, we aimed to explore the function of verbascoside (VB) in GBM and its effects on GBM cell biological processes via let-7g-5p and HMGA2. Differentially expressed GBM-related microRNAs (miRNAs) were initially screened. Different concentrations of VB were applied to U87 and U251 GBM cells, and 50 µmol/L of VB was selected for subsequent experiments. Cells were transfected with let-7g-5p inhibitor or mimic, and overexpression of HMGA2 or siRNA against HMGA2 was induced, followed by treatment with VB. The regulatory relationships between VB, let-7g-5p, HMGA2 and Wnt/ß-catenin signalling pathway were determined. The results showed that HMGA2 was a direct target gene of let-7g-5p. VB treatment or let-7g-5p overexpression inhibited HMGA2 expression and the activation of Wnt/ß-catenin signalling pathway, which further inhibited cell viability, invasion, migration, tumour growth and promoted GBM cell apoptosis and autophagy. On the contrary, HMGA2 overexpression promoted cell viability, invasion, migration, tumour growth while inhibiting GBM cell apoptosis and autophagy. We demonstrated that VB inhibits cell viability and promotes cell autophagy in GBM cells by up-regulating let-7g-5p and down-regulating HMGA2 via Wnt/ß-catenin signalling blockade.

Hurdle enhancement of acidic electrolyzed water antimicrobial efficacy on Bacillus cereus spores using ultrasonication.

This study evaluated the inactivation effect of ultrasonic treatment combined with acidic electrolyzed water (AEW) on Bacillus cereus spores. AEW treatment reduced the spores by 1.05-1.37 log CFU/mL while the sporicidal effect of ultrasound was minor. More strikingly, simultaneous ultrasonic and AEW treatments for 30 min led to 2.29 log CFU/mL reduction and thus, considered a synergistic effect. Flow cytometry combined with SYTO/PI staining analysis revealed that ultrasound hydrolyzed the cortex while the AEW partially damaged the integrity of the inner membrane. Scanning and transmission electron microscopies were used to characterize the ultrastructural changes. The detachment of the exosporium induced by ultrasound was the most apparent difference compared with the control group, and the electron density of spores appeared to be heterogeneous after treatment with AEW. These results indicated that combining ultrasound with AEW is a promising decontamination technology with potential uses in the food industry and environmental remediation.

Mesopore Engineering for Well-Defined Mesoporosity in Al-Rich Aluminosilicate Zeolites.

Desilication has been proven an effective approach for the construction of well-defined hierarchical porosities inside zeolites with an optimal framework Al content (Si/Al=25-50). However, for the Al-rich aluminosilicate zeolites, desilication is constrained by the excess and extensive shielding effects from high Al-contents. The developments in the desilication of siliceous zeolites convey a simplified principle of controlled dissolution of the microporous matrix for the construction of hierarchical porosities, which benefits the innovation of synthetic approaches for Al-rich zeolites. The perturbations to the environments of framework Al species may alleviate the excess shielding effects. This review highlights two corresponding protocols of sequential "fluorination-desilication" and "steaming-desilication" for the construction of hierarchical porosities inside Al-rich ZSM-5 zeolites. The success of these two protocols revitalizes the prevailing understanding of the interplay between dealumination and desilication, and implies the necessity of investigating the overlooked roles of extra-framework Al species. Despite the long history and significant achievements in the last decade, fundamental understandings at the molecule level are still limited for the desilication-based top-down approaches. In particular, the investigations on Al-rich zeolites just find their growing. The bridging of dealumination and desilication is essential for other industrially relevant Al-rich zeolites (e.g., faujasite zeolites). The complexities in the inherent characters (topology, spatial distribution, proximity, etc.) and apparent parameters (morphology, crystal/particle size, etc.) demand constructive synthetic toolboxes and further fundamental understanding.

Effect of ultrasonication and thermal and pressure treatments, individually and combined, on inactivation of Bacillus cereus spores.

Bacillus cereus spores are a concern to the food industry due to their high resistance to processing and their ability to germinate to vegetative cells under suitable conditions. This research aimed to elucidate the mechanisms of Bacillus cereus spore inactivation under ultrasonication (US) combined with thermal (thermosonication, TS) treatments, with pressure (manosonication, MS) treatments, and with thermal and pressure (manothermosonication, MTS) treatments. Electronic microscopy, dipicolinic acid (DPA) release, and flow cytometric assessments were used to investigate the inactivation effect and understand the inactivation mechanisms. The sporicidal effects of the US and thermal treatment were slight, and the MS and TS also showed little inactivation effect. However, ultrasonication promoted the detachment of the exosporium, thereby reducing the spore's ability to adhere to a surface, while the thermal treatment induced a decrease in the electron density in the nucleoid of bacterium, which retained a relatively intact exosporium and coat. MS caused 92.54% DPA release, which might be due to triggering of the germinant receptors or releasing of ions and Ca2+-DPA. In addition, the morphological changes such as core hydration and cortex degradation were significant after treatment with MS. The release of DPA and the morphological changes were responsible for the reduction in thermal resistance. The MTS showed a remarkable inactivation effect of 3.12 log CFU/mL reductions after 30 min of treatment. It was the most effective treatment and exhibited a large fraction of damage. In addition, the MTS had a significant impact on the intracellular structure of the spores, with the coat destroyed and the cortex damaged. These results indicated that ultrasonication combined with thermal and pressure treatments had a significant sporicidal effect on Bacillus cereus spores and could be a promising green sterilization technology.

Verbascoside Inhibits Glioblastoma Cell Proliferation, Migration and Invasion While Promoting Apoptosis Through Upregulation of Protein Tyrosine Phosphatase SHP-1 and Inhibition of STAT3 Phosphorylation.

BACKGROUND/AIMS: As a natural antioxidant, verbascoside (VB) is proved to be a promising method for the treatment of oxidative-stress-related neurodegenerative diseases. Thus, this study aimed to investigate the effects of VB on glioblastoma cell proliferation, apoptosis, migration, and invasion as well as the mechanism involving signal transducer and activator of transcription 3 (STAT3) and Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1). METHODS: U87 cells were assigned to different treatments. The MTT assay was used to test cell proliferation, flow cytometry was used to detect cell apoptosis, and a Transwell assay was used for cell migration and invasion. We analyzed the glioblastoma tumor growth in a xenograft mouse model. Western blot analysis was employed to determine the protein expression of related genes. RESULTS: Glioblastoma cells exhibited decreased cell proliferation, migration, invasion, and increased apoptosis when treated with VB or TMZ. Western blot analysis revealed elevated SHP-1 expression and reduced phosphorylated (p)-STAT3 expression in glioblastoma cells treated with VB compared with controls. Correspondingly, in a xenograft mouse model treated with VB, glioblastoma tumor volume and growth were decreased. Glioblastoma xenograft tumors treated with VB showed elevated SHP-1, Bax, cleaved caspase-3, and cleaved PARP expression and reduced p-STAT3, Bcl-2, survivin, MMP-2, and MMP-9 expression. siRNA-SHP-1 inhibited the VB effects on glioblastoma. CONCLUSION: This study demonstrates that VB inhibits glioblastoma cell proliferation, migration, and invasion while promoting apoptosis via SHP-1 activation and inhibition of STAT3 phosphorylation.

W-N-TiO2 with positive enough level of valence band maximum and narrowing bandgap for selective aerobic oxidation in visible-light irradiation.

A kind of surface complex (triethylamine and mesoporous W-N-TiO2 microspheres with large surface area: 117.5 m2g-1) catalysis was achieved via visible-light photoredox catalysis. Triethylamine behaves as a true redox mediator due to its highly favorable donating ability. With a lower bandgap (2.43 eV) and higher valence band maximum (2.905 V), W-N-TiO2 has the ability to play an active catalytic role yielding excellent conversion and selective oxidation of thioanisole (75.16%) within 12 h under visible-light irradiation. In addition, the reaction and the photocatalyst are applicable to other kinds of thioethers, generally producing high conversion rates and selectivities for the product sulfoxides. The reaction paths were elucidated to reveal that these kinds of surface complexes show characteristics that are likely to be applicable to many aerobic oxidation reactions in future.

Soft-Template Synthesis of Mesoporous Anatase TiO2 Nanospheres and Its Enhanced Photoactivity.

Highly crystalline mesoporous anatase TiO2 nanospheres with high surface area (higher than P25 and anatase TiO2) are prepared by a soft-template method. Despite the high specific surface area, these samples have three times lower equilibrium adsorption (<2%) than Degussa P25. The rate constant of the mesoporous anatase TiO2 (0.024 min-1) reported here is 364% higher than that of P25 (0.0066 min-1), for the same catalytic loading. The results of oxidation-extraction photometry using several reactive oxygen species (ROS) scavengers indicated that mesoporous anatase TiO2 generates more ROS than P25 under UV-light irradiation. This significant improvement in the photocatalytic performance of mesoporous spherical TiO2 arises from the following synergistic effects in the reported sample: (i) high surface area; (ii) improved crystallinity; (iii) narrow pore wall thicknesses (ensuring the rapid migration of photogenerated carriers to the surface of the material); and (iv) greater ROS generation under UV-light.

Bridging Dealumination and Desilication for the Synthesis of Hierarchical MFI Zeolites.

The rational design of zeolite-based catalysts calls for flexible tailoring of porosity and acidity beyond micropore dimension. To date, dealumination has been applied extensively as an industrial technology for the tailoring of zeolite in micropore dimension, whereas desilication has separately shown its potentials in the creation of mesoporosities. The free coupling of dealumination with desilication will bridge the tailoring at micro/mesopore dimensions; however, such coupling has been prevailingly confirmed as an impossible mission. In this work, a consecutive dealumination-desilication process enables the introduction of uniform intracrystalline mesopores (4-6 nm) into the microporous Al-rich zeolites. The decisive impacts of steaming step have been firstly discovered. These findings revitalize the functions of dealumination in porosity tailoring, and stimulate the pursuit of new methods for the tailoring of industrially relevant Al-rich zeolites.

Curcumin improves neural function after spinal cord injury by the joint inhibition of the intracellular and extracellular components of glial scar.

BACKGROUND: Spinal cord injury (SCI) is characterized by a high rate of disability and imposes a heavy burden on society and patients. SCI can activate glial cells and lead to swelling, hyperplasty, and reactive gliosis, which can severely reduce the space for nerve growth. Glial cells can secrete a large amount of extracellular inhibitory components, thus altering the microenvironment of axon growth. Both these factors seriously impede nerve regeneration. In the present study, we investigate whether curcumin (cur), a phytochemical compound with potent anti-inflammatory effect, plays a role in the repair of SCI. MATERIALS AND METHODS: We established a rat model of SCI and treated the animals with different concentrations of cur. Using behavioral assessment, immunohistochemistry, real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay, we detected the intracellular and extracellular components of glial scar and related cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, nuclear factor (NF)-κb, transforming growth factor (TGF)-ß1, TGF-ß2, and sex determining region Y-box (SOX)-9. RESULTS: We found that cur inhibited the expression of proinflammatory cytokines, such as TNF-α, IL-1ß, and NF-κb; reduced the expression of the intracellular components glial fibrillary acidic protein through anti-inflammation; and suppressed the reactive gliosis. Also, cur inhibited the generation of TGF-ß1, TGF-ß2, and SOX-9; decreased the deposition of chondroitin sulfate proteoglycan by inhibiting the transforming growth factors and transcription factor; and improved the microenvironment for nerve growth. Through the joint inhibition of the intracellular and extracellular components of glial scar, cur significantly reduced glial scar volume and improved the Basso, Beattie, and Bresnahan locomotor rating and axon growth. CONCLUSIONS: Our data support a role for curcumin in promoting neural function recovery after SCI by the joint inhibition of the intracellular and extracellular components of glial scar, providing an important strategy for treating SCI.

Curcumin increased the differentiation rate of neurons in neural stem cells via wnt signaling in vitro study.

BACKGROUND: The objective of the present study was to clarify the relationship between the neuroprotective effects of curcumin and the classical wnt signaling pathway. METHOD: Using Sprague-Dawley rats at a gestational age of 14.5 d, we isolated neural stem cells from the anterior two-thirds of the fetal rat brain. The neural stem cells were passaged three times using the half media replacement method and identified using cellular immunofluorescence. After passaging for three generations, we cultured cells in media without basic fibroblast growth factor and epidermal growth factor. Then we treated cells in five different ways, including a blank control group, a group treated with IWR1 (10 µmol/L), a group treated with curcumin (500 nmol/L), a group treated with IWR1 + curcumin, and a group treated with dimethyl sulfoxide (10 µmol/L). We then measured the protein and RNA expression levels for wnt3a and ß-catenin using Western blotting and Reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Western-blotting: after the third generation of cells had been treated for 72 h, we observed that wnt3a and ß-catenin expression was significantly increased in the group receiving 500 nmol/L curcumin but not in the other groups. Furthermore, cells in the IWR1-treated group showed decreased wnt3a and ß-catenin expression, and wnt3a and ß-catenin was also decreased in the IWR1 + 500 nmol/L curcumin group. No obvious change was observed in the dimethyl sulfoxide group. RT-PCR: RT-PCR showed similar changes to those observed with the Western blotting experiments. CONCLUSIONS: Our study suggests that curcumin can activate the wnt signaling pathway, which provides evidence that curcumin exhibits a neuroprotective effect through the classical wnt signaling pathway.

The chromosome-level genome assembly of the giant dobsonfly Acanthacorydalis orientalis (McLachlan, 1899).

Acanthacorydalis orientalis (McLachlan, 1899) (Megaloptera: Corydalidae) is an important freshwater-benthic invertebrate species that serves as an indicator for water-quality biomonitoring and is valuable for conservation from East Asia. Here, a high-quality reference genome for A. orientalis was constructed using Oxford Nanopore sequencing and High throughput Chromosome Conformation Capture (Hi-C) technology. The final genome size is 547.98 Mb, with the N50 values of contig and scaffold being 7.77 Mb and 50.53 Mb, respectively. The longest contig and scaffold are 20.57 Mb and 62.26 Mb in length, respectively. There are 99.75% contigs anchored onto 13 pseudo-chromosomes. Benchmarking Universal Single-Copy Orthologs (BUSCO) analysis showed that the completeness of the genome assembly is 99.01%. There are 10,977 protein-coding genes identified, of which 84.00% are functionally annotated. The genome contains 44.86% repeat sequences. This high-quality genome provides substantial data for future studies on population genetics, aquatic adaptation, and evolution of Megaloptera and other related insect groups.

Experimental high-altitude intracerebral hemorrhage in minipigs: histology, behavior, and intracranial pressure in a double-injection model.

BACKGROUND: Specific pathophysiological mechanism in intracerebral hemorrhage (ICH) at high altitude is unclear, and at present, there is no relevant and suitable animal model. METHODS: A hypobaric chamber was used to simulate an altitude of 4,000 m. Autologous arterial blood (3 ml) was slowly infused into the right basal ganglia of minipigs by a double-injection method for producing ICH. RESULTS: The intracranial pressure and neurological score of the high-altitude group were significantly higher than those of the low-altitude (plain) group. The brain water contents and pathological lesions of perihematoma tissue were more severe in the high-altitude group. CONCLUSIONS: The injury resulting from ICH at high altitude was more severe than that in the plain group. This model was able to produce controllable and reproducible hematomas and visible neurological deficits, which may be useful for future studies of the pathophysiology and functional rehabilitation of high-altitude ICH disease.

Deficiency of TRIM32 Impairs Motor Function and Purkinje Cells in Mid-Aged Mice.

Proper functioning of the cerebellum is crucial to motor balance and coordination in adult mammals. Purkinje cells (PCs), the sole output neurons of the cerebellar cortex, play essential roles in cerebellar motor function. Tripartite motif-containing protein 32 (TRIM32) is an E3 ubiquitin ligase that is involved in balance activities of neurogenesis in the subventricular zone of the mammalian brain and in the development of many nervous system diseases, such as Alzheimer's disease, autism spectrum disorder, attention deficit hyperactivity disorder. However, the role of TRIM32 in cerebellar motor function has never been examined. In this study we found that motor balance and coordination of mid-aged TRIM32 deficient mice were poorer than those of wild-type littermates. Immunohistochemical staining was performed to assess cerebella morphology and TRIM32 expression in PCs. Golgi staining showed that the extent of dendritic arborization and dendritic spine density of PCs were decreased in the absence of TRIM32. The loss of TRIM32 was also associated with a decrease in the number of synapses between parallel fibers and PCs, and in synapses between climbing fibers and PCs. In addition, deficiency of TRIM32 decreased Type I inositol 1,4,5-trisphosphate 5-phosphatase (INPP5A) levels in cerebellum. Overall, this study is the first to elucidate a role of TRIM32 in cerebellar motor function and a possible mechanism, thereby highlighting the importance of TRIM32 in the cerebellum.

Evaluation of antimicrobial and antibiofilm properties of proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves against Staphylococcus epidermidis.

Staphylococcus epidermidis has emerged in recent years as one of the most important opportunistic pathogens owing to its ability to attach to processing surfaces in the food industry. Demands of foodstuffs maintaining microbiological safety and stability enhance the need to develop natural antimicrobial agents as food preservatives. Proanthocyanidins from Chinese bayberry leaves (BLPs) belonging to the class of polyphenols promise to be a potential antibacterial material against bacterial adhesion and biofilm formation. The aim of the present study was to investigate the effects of BLPs on S. epidermidis growth and biofilm formation. BLPs possessed antimicrobial activity with MIC and MBC of 320 and 640 µg/ml, respectively. Scanning electron microscopy, transmission electron microscopy, and flow cytometry analysis revealed a loss of the cell structure and function after treatment of BLPs, evidenced by cell membrane hyperpolarization and changes in cellular morphology. BLPs inhibited the biofilm formation by S. epidermidis on polystyrene microplates. Atomic force microscopy analysis showed that BLPs could decrease the stiffness and adhesion force of the cell envelope, which might account for the inhibition of biofilm formation. In summary, this study indicated that BLPs have potential to be developed as natural preservatives to control S. epidermidis in foods.

Co-Encapsulation of EGCG and Quercetin in Liposomes for Optimum Antioxidant Activity.

Although different delivery systems have been developed to overcome the limits of Epigallocatechin-3-gallate (EGCG) and quercetin in food application, none have referred to their simultaneous encapsulation. In this study, these two polyphenols were successfully co-loaded into liposomes. Under the optimal conditions (lecithin-total polyphenols ratio 25:1, lecithin-cholesterol ratio 6:1, lecithin-Tween 80 ratio 8:1 and ultrasonic time 2 min), the mean size, polydispersity index (PDI) and zeta potential of liposomes were 111.10 ± 0.52 nm, 0.259 ± 0.006 and -19.83 ± 0.45 mV, with an encapsulation efficiency of 64.05 ± 1.56% and 61.73 ± 2.55% for EGCG and quercetin, respectively. After 30-day storage, an increase of 4.05% was observed in the mean size with no significant change (P ≥ 0.05) in the PDI and zeta potential. Moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed a synergistic antioxidant effect of the two compounds in liposomal system. These results demonstrated that co-encapsulation of EGCG and quercetin enhances their effectiveness. PRACTICAL APPLICATION: EGCG and quercetin are natural polyphenols abound in the human diet with diverse biological activities. These two polyphenols were successfully co-encapsulated into a homogeneous and stable liposomal system. Interestingly, a synergistic antioxidant effect of the two polyphenols was observed due to co-encapsulation. This indicated that the simultaneous delivery of EGCG and quercetin was an attractive approach to improve their functionality for expanding their application in food, cosmetic and pharmaceutical industries.

Thermosonication damages the inner membrane of Bacillus subtilis spores and impels their inactivation.

The extreme resistance of bacterial spores to most killing agents makes them a major concern to the food industry and consumers. This gave rise an increasing interest in developing new strategies to inactivate spores and understand the mechanisms of inactivation by various agents. In this study, ultrasound combined with heat (thermosonication, TS) was used to inactivate the spores of Bacillus subtilis and the factors that influence the resistance to TS were analyzed. The spores of wild-type B. subtilis and isogenic mutants were subjected to heat at 80 °C and ultrasound at 6.67-20 W/mL and 23 °C for 0-40 min. TS treatment has synergistically resulted in spore inactivation, and spores of wild-type B. subtilis and isogenic mutants showed different resistance to TS treatment, which was in the following order: Strains 533 (wild-type) ≈ strains PS3518 (gfp) ≈ strains PS2318 (recA-) > strains PS578 (α-ß-), and spores of strains PS3328 (cotE-) were also more susceptible than those of wild-type strains. The inactivated spores lost some proteins in the spore core but initiated germination normally. The germinated inactivated spores did not swell and their plasma membrane permeability was equally altered. It was concluded that the damage to spores' inner membrane (IM) proteins or the IM itself has led to the leakage of intracellular substances and the death of a spore by TS treatment. Our results could support the development and optimization of TS treatment, which has great significance for its further utilization in food industry.

A systematic characterization of the distribution, biofilm-forming potential and the resistance of the biofilms to the CIP processes of the bacteria in a milk powder processing factory.

Owing to the resistance to conventional cleaning and sanitizing agents, biofilms formed on surfaces of dairy processing equipment pose a hazard to the dairy industry. The objective of this study was to evaluate the diversity of the microflora attached to various surfaces of the processing lines of a milk powder processing factory based on 16S rRNA gene sequence analysis. The production of biofilms by the bacterial strains was evaluated on polystyrene (PS) and stainless-steel (SS) surfaces by crystal violet staining method. Especially, effects of temperatures (e.g., 37 °C and 55 °C) and growth mediums (e.g., nutrient broth, NB; tryptic soy broth, TSB) on the production of biofilms by these strains on PS surfaces were explored. Besides, the tolerance of the biofilms of the strains to CIP processes (1.5% v/v HNO3 solution or 2.0% w/v NaOH solution at 80 °C) were analyzed. Forty-five isolates from eleven interior surfaces of the facilities were identified and the distribution of strains had high species diversity, which indicated that multiple spoilage and pathogenic microorganisms remained in milk powder processing lines after CIP processes. Bacteria showed higher biofilm-forming abilities on SS compared to PS surfaces under the same condition. Moreover, effects of the incubation temperature and growth medium on biofilm formation varied between genera, species, and strains. One strain of each species with biofilm-forming abilities on SS surfaces was selected to check the resistance of their biofilms formed on SS coupons to the CIP processes. Biofilms of all of the nine strains were highly or moderately alkali and acid resistant, posing a threat to the milk powder production. These results suggested that organisms within the biofilm might withstand temperature and pH changes better than planktonic organisms. More research is needed to investigate different species isolated from different facilities of the processing lines and to improve the key controlling points in the CIP processes.

Ultrasound promotes enzymatic reactions by acting on different targets: Enzymes, substrates and enzymatic reaction systems.

With the extensive application of enzyme-catalyzed reactions in numerous fields, improving enzymatic efficiency has attracted wide attention for reducing operating costs and increasing output. There are three targets throughout enzymatic reactions: the enzyme, substrate, and mixed reaction system. Ultrasound has been known to accelerate enzymatic reactions by acting on different targets. It can modify both enzyme and substrate macromolecules, which is helpful for enhancing enzyme activity and product yields. The synergistic effect of ultrasound and enzymes is widely reported to increase catalytic rates. The present review discusses the positive effect induced by ultrasound throughout the enzymatic process, including ultrasonic modification of enzymes, ultrasound assisted immobilization, ultrasonic pretreatment of substrates, and ultrasound assisted enzymatic reactions.