Eating behaviors and associated factors among preschool children in Tongling City / 中国学校卫生

Objective@#To examine the eating behaviors and associated factors among preschool children from multiple child families, so as to provide a basis for promoting healthy eating habits in this population.@*Methods@#From April to June 2022, a stratified random cluster sampling method was employed to selected 2 647 guardians of preschool children in 11 kindergartens in Tongling City. Parenting style questionnaire, Identification and Management of Feeding Difficulty Questionnaire (IMFeD), Caregiver s Feeding Style Questionnaire (CFSQ) and a self designed questionnaire were administered. Multiple linear regression was performed to analyze the factors influencing eating behaviors among preschool children.@*Results@#In the study, the detection of eating behavior problems among preschool children was 71.4%, and the detection of reduced appetite was the highest (55.6%). The detection rates of anorexia, picky eating, poor eating and improper eating behavior in only child families were higher (60.6%, 41.0%, 32.0%, 19.5%), compared with those in multiple child families (51.7%, 36.4%, 27.2%, 16.6%) ( χ 2=20.05, 5.95, 7.16, 3.92, P < 0.05 ). Among multiple child families, the detection rates of fear of eating and underlying disease were the lowest in 5-<10-year-old group (2.3%, 0.6%) ( χ 2=11.54, 8.51, P <0.05). In multiple child families, the detection rates of picky eating and poor eating habits for the first-born child were higher (42.0%, 32.5%), compared with second born and third born child (34.6%, 25.6%)( χ 2= 6.15, 6.38, P <0.05). The results of multiple linear regression analysis showed that multiplechild families ( β =-1.40), democratic parenting style ( β =-0.07), higher feeding response scores ( β =-0.33) were negatively associated with eating behavior problems among preschool children ( P <0.05). Eating behavior problems among preschool children were positively correlated with less educated mothers [high and junior high school education ( β =0.87), primary school education and below ( β =3.69)], longer average daily screen time ( β =0.10), higher feeding requirements scores ( β =0.64), doting parenting styles ( β =0.21), permissive parenting styles ( β =0.27) and inconsistent parenting styles ( β =0.14)( P <0.05).@*Conclusion@#The detection rate of the eating behaviors problems among preschool children is high in schools. Greater attention should be paid to only child and first born child of multiple child families, and appropriate feeding and parenting styles, so as to promote healthy eating habits among this population.

Comparison of emotional and behavioral problems of preschool children in only child and multiple child families / 中国学校卫生

Objective@#To explore the emotional and behavioral problems of different only child and multiple child families, and to provide a reference for developing effective parenting styles.@*Methods@#A stratified random cluster sampling method was adopted to investigate 2 647 guardians of preschool children in Tongling City from April to June, 2022. Children s emotional and behavioral problems were evaluated by using the self designed parenting questionnaire and the Children s Strengths and Difficulties Questionnaire (SDQ) parent edition.@*Results@#The abnormal total score detection rate of emotional and behavioral problems of preschool children was 15.5%, and the rate of abnormal peer interaction was the highest (19.5%). In multiple child families, the first born child (17.5%, 20.4%), compared with the second and third child (11.5%, 9.5%), was more likely to exhibit conduct and hyperactivity problems ( χ 2=8.44, 29.75, P <0.01). There were differences in parenting attitudes between only child and multiple child families( χ 2=9.38, P <0.05). The results of the Logistic regression analysis showed that more frequent parent child discussion, the persuasive education and consistent family discipline strategy were negatively related to the emotional and behavioral problems of only children and children in multiple child families ( OR =0.15, 0.49, 0.38; 0.34, 0.40, 0.42, P <0.05). However, harmonious family relationships were only negatively related to emotional and behavioral problems in only children ( OR =0.08, P <0.01), and a higher education level among mothers was negatively related to emotional and behavioral problems in children from multiple child family environments( OR=0.30, 0.45, P <0.05).@*Conclusion@#The emotional and behavioral problems are serious of preschool children in Tongling City, the psychological development of the oldest children from multiple child and only child families should be actively followed, as this would help to promote a better understanding of the development of preschool children s physical and mental health.

Non-Destructive Testing of Carbon Fibre Reinforced Plastics (CFRP) Using a Dual Transmitter-Receiver Differential Eddy Current Test Probe.

Transmitter-receiver (T-R) probes are widely used in the eddy-current testing of carbon fibre reinforced plastics (CFRP). However, T-R probes have the disadvantage of being highly sensitive to lift-off. On this basis, lift-off interference can be eliminated by differential structure. However, due to the electrical anisotropy of CFRP, the detection sensitivity of the side-by-side T-R probe and traditional R-T-R differential probe are greatly affected by the scanning angle, and the probe often needs to scan the sample along a specific path to achieve the ideal required detection effect. To solve these problems, a symmetrical dual-transmit-dual-receive (TR-TR) differential probe is designed in this paper. The detection performance of the TR-TR probe was verified by simulation and experiments. Results show that the TR-TR probe is less affected by the scanning angle and lift-off when used in CFRP defect detection, and has high detection sensitivity. However, the imaging results of the TR-TR probe do not show the defect characteristics straightforwardly. To solve this problem, a defect feature extraction algorithm is proposed in this paper. The results show that the defect feature extraction algorithm can locate and size the defect more accurately and improve the signal-to-noise ratio.

Triamcinolone acetonide injection in the treatment of upper eyelid retraction in Graves' ophthalmopathy evaluated by 3.0 Tesla magnetic resonance imaging.

Purpose: To evaluate changes in the levator palpebrae superioris (LPS) muscle on 3.0 T magnetic resonance imaging (MRI) after triamcinolone acetonide injection for treating upper lid retraction (ULR) with Graves' ophthalmopathy (GO) and to explore the value of LPS muscle quantitative measurement for clinical treatment. Methods: Patients with GO showing ULR were studied retrospectively and they underwent 3.0 T MRI scans before and after subconjunctival injection o f triamcinolone acetonide. The largest thickness (T) and highest signal intensity (SI) of LPS muscle on the affected eyes were measured in the sequences of coronal T2-weighted, fat-suppressed fast spin echo imaging (T2WI-fs) and T1-weighted, fat-suppressed, contrast-enhanced fast spin echo imaging (T1WI-fs + C), respectively. The SI ratio (SIR) (LPS muscle SI/ipsilateral temporalis SI) was calculated individually. Depending on the therapeutic effect, patients were divided into effective group and non-effective group. Independent t-test was used to compare SIR and T of LPS muscle in different treatment groups before treatment, and paired sample t-test was used to compare SIR and T of LPS muscle before and after treatment. Then cut-off level for predicting therapeutic effect and the receiver operating characteristic curve (ROC) curve were analyzed. Results: Sixty-two patients (77 eyes) were enrolled. After treatment, the T of LPS muscle showed significant decrease in all sequences in both effective and non-effective treatment groups. However, changes in SIR of LPS muscle in the two groups were different; SIR of LPS muscle on T2WI-fs and T1WI-fs + C decreased after treatment in the effective group (PT2 < 0.001, PT1 + C < 0.001) and SIR of LPS muscle showed no statistically difference in all sequences (all P > 0.05) in the non-effective group. There was a correlation between SIR of LPS muscle before treatment and after treatment with triamcinolone acetonide injection, which was that SIR of LPS muscle in the effective treatment group was lower than that in the non-effective treatment group on T1WI-fs + C (P < 0.001). SIR of LPS muscle on T1WI-fs + C showed 87.5% sensitivity and 66.7% specificity to predict therapeutic effect (area under the ROC curve [AUC] = 0.840). Conclusion: In GO patients with ULR, 3.0 T MRI can be used to evaluate the response of triamcinolone acetonide injection. SIR of LPS may be a predictor of its efficacy.

Relationship between parental rearing style and emotional and behavioral problems of 3-6-year-old children / 中国学校卫生

Objective@#To understand emotional and behavioral problems of children aged 3-6 years, and to explore the role of parenting style in the development of those problems.@*Methods@#A total of 2 278 children from 11 public kindergartens in Tongling City from April to June 2018 were selected by cluster sampling method. The questionnaire was made up by parents. The questionnaire mainly included: children, basic information of parents and children, children’s psychology and behavior, and parents’ education style, etc.@*Results@#Among 2 278 children, 192(8.43%) had abnormal emotional symptoms, 214 (9.39%) had conduct problems, 376(16.50%) had hyperactivity problems, 537(23.57%) had peer problems, 233(10.2%) had abnormal total difficulty scores and 254(11.15%) had prosocial behaviors. Gender, age, health status of the child, second-hand smoke exposure of the baby, parents’ education level, family economic conditions, and parents’ education mode are all the influencing factors of children’s emotion and behavior(P<0.05). Logistic analysis showed that father’s support participation(OR=0.96, 95%CI=0.95-0.98), mother’s support participation (OR=0.94, 95%CI=0.92-0.95), mother’s hostility compulsion (OR=1.08, 95%CI=1.06-1.10) and 3-6-year-old children’s abnormal mood and behavior were correlated(P<0.01).@*Conclusion@#Parental support and maternal hostile are related to emotional and behavioral problems of 3-6-year-old children.

Protective effect of N-acetylcysteine activated carbon release microcapsule on myocardial ischemia-reperfusion injury in rats.

With the development of science and technology, and development of artery bypass, methods such as cardiopulmonary cerebral resuscitation have been practiced in recent years. Despite this, some methods fail to promote or recover the function of tissues and organs, and in some cases, may aggravate dysfunction and structural damage to tissues. The latter is typical of ischemia-reperfusion (IR) injury. Lipid peroxidation mediated by free radicals is an important process of myocardial IR injury. Myocardial IR has been demonstrated to induce the formation of large numbers of free radicals in rats, which promotes the peroxidation of lipids within unsaturated fatty acids in the myocardial cell membrane. Markers of lipid peroxidation include malondialdehyde, superoxide dismutase and lactic dehydrogenase. Recent studies have demonstrated that N-acetylcysteine (NAC) is able to dilate blood vessels, prevent oxidative damage, improve immunity, inhibit apoptosis and the inflammatory response and promote glutathione synthesis in cells. NAC also improves the systolic function of myocardial cells and cardiac function, prevents myocardial apoptosis, protects ventricular remodeling and vascular remodeling, reduces opiomelanocortin levels in the serum and increases the content of nitric oxide in the serum, thus improving vascular endothelial function. Therefore, NAC has potent pharmacological activity; however, the relatively fast metabolism of NAC, along with its large clinical dose and low bioavailability, limit its applications. The present study combined NAC with medicinal activated carbons, and prepared N-acetylcysteine activated carbon sustained-release microcapsules (ACNACs) to overcome the limitations of NAC. It was demonstrated that ACNACs exerted greater effective protective effects than NAC alone on myocardial IR injury in rats.

N,N'-diacetylcystine ameliorates inflammation in experimental non-alcoholic steatohepatitis by regulating nuclear transcription factor kappa B activation.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases worldwide that has been continuously increasing recently. NAFLD embraces a spectrum of liver histological alterations, ranging from simple steatosis (NAFL) to severe non-alcoholic steatohepatitis (NASH), that is characterized by fat accumulation, lobular inflammation, and ballooning degeneration in the hepatocytes in the absence of alcohol abuse. The innate immune system has an important role in NASH pathogenesis. Among the components of innate immunity, the nuclear factor kappa B (NF-κB) has been closely associated with NASH. N,N'-diacetylcystine (DiNAC), the disulfide dimer of N-acetylcysteine (NAC), is a potent modulator of the immune system. Previous research has confirmed that DiNAC has beneficial effects in liver injury. In this study, we aimed to investigate the effects of DiNAC on high fat diet (HFD)-induced NASH in rats. Male Sprague-Dawley rats were fed with HFD to produce the NASH model and treated with or without DiNAC for 8 weeks. We assessed serum levels of alanine-aminotransferase (ALT), aspartate aminotransferase (AST), inflammatory cytokines, liver histology, and the expression of NF-κB genes in the liver. The results showed that the levels of ALT and AST were significantly increased in the HFD rat model. DiNAC treatment also resulted in a statistically significant reduction of the levels of ALT and AST. Hematoxylin and eosin (H&E) staining revealed that DiNAC alleviated histological injury. Moreover, DiNAC strongly reduced the generation of inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) and interleukin-1ß (IL-1ß), through NF-κB downregulation. Taken together, these results indicate that DiNAC treatment effectively delayed the progression of NASH by suppressing the expression of NF-κB mRNA in the liver. Our data suggest that DiNAC protects liver injury in HFD-treated NASH rats, which might be a promising drug for the treatment of NASH.

Effects of activated carbon N-acetylcysteine sustained-release microcapsule on dipeptidyl peptidase IV expression in young rats with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) in children has become the most common liver disease influencing adolescent health and one of the most influencing chronic liver diseases among children in Chinese wealthy families, particularly in coastal regions. However, the medicine available for the treatment of NAFLD is deficient. In order to solve this problem, our team studied the activated carbon N-acetylcysteine (NAC) sustained-release microcapsule, which improves the oxidation resistance, bioavailability and drug stability of acetylcysteine and reduces toxic and side effects. In addition, it accords with the characteristics of medication in infants and children. The present study mainly discusses whether the activated carbon NAC sustained-release microcapsule has effects on dipeptidyl peptidase IV (DPPIV) activity and protein in young rats with NAFLD, and whether it has the effect of an DPPIV inhibitor, hoping to provide new thoughts and methods with respect of basic studies on young rats with NAFLD/non-alcoholic steatohepatitis.

Cerebral Functional Reorganization in Ischemic Stroke after Repetitive Transcranial Magnetic Stimulation: An fMRI Study.

AIMS: Our study aimed to figure out brain functional reorganization evidence after repetitive transcranial magnetic stimulation (rTMS) using the resting-state functional magnetic resonance imaging (rsfMRI). METHODS: Twelve patients with unilateral subcortex lesion in the middle cerebral artery territory were recruited. Seven of them received a 10-day rTMS treatment beginning at about 5 days after stroke onset. The remaining five received sham treatment. RsfMRI and motor functional scores were obtained before and after rTMS or sham rTMS. RESULTS: The rTMS group showed motor recovery according to the behavioral testing scores, while there was no significant difference of motor functional scores in the sham group before and after the sham rTMS. It proved that rTMS facilitates motor recovery of early ischemic stroke patients. Compared with the sham, the rTMS treatment group achieved increased functional connectivity (FC) between ipsilesional M1 and contralesional M1, supplementary motor area, bilateral thalamus, and contralesional postcentral gyrus. And decreased FC was found between ipsilesional M1 and ipsilesional M1, postcentral gyrus and inferior and middle frontal gyrus. CONCLUSION: Increased or decreased FC detected by rsfMRI is an important finding to understand the mechanism of brain functional reorganization. The rTMS treatment is a promising therapeutic approach to facilitate motor rehabilitation for early stroke patients.

N-acetylcysteine protects against liver injure induced by carbon tetrachloride via activation of the Nrf2/HO-1 pathway.

Chronic liver injury is an important clinical problem which eventually leads to cirrhosis, hepatocellular carcinoma and end-stage liver failure. It is well known that cell damage induced by reactive oxygen species (ROS) is an important mechanism of hepatocyte injure. N-acetylcysteine (NAC), a precursor of glutathione (GSH), is well-known role as the antidote to acetaminophen toxicity in clinic. NAC is now being utilized more widely in the clinical setting for non-acetaminophen (APAP) related causes of liver injure. However, the mechanisms underlying its beneficial effects are poorly defined. Thus, Aim of the present study was to investigate potential hepatic protective role of NAC and to delineate its mechanism of action against carbon tetrachloride (CCl4)-induced liver injury in models of rat. Our results showed that the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities as well as malondialdehyde (MDA) contents decreased significantly in CCl4-induced rats with NAC treatment. GSH content and superoxide dismutase (SOD) activities remarkably increased in the NAC groups compared with those in CCl4-induced group. Treatment with NAC had been shown to an increase in nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) mRNA levels. In conclusion, these results suggested that NAC upregulated HO-1 through the activation of Nrf2 pathway and protected rat against CCl4-induced liver injure. The results of this study provided pharmacological evidence to support the clinical application of NAC.

Protective effects of N-acetylcysteine on cisplatin-induced oxidative stress and DNA damage in HepG2 cells.

Hepatocyte injury is a common pathological effect of cisplatin (CDDP) in various solid tumor therapies. Thus, strategies for minimizing CDDP toxicity are of great clinical interest. N-acetylcysteine (NAC), a known antioxidant, is often used as an antidote for acetaminophen overdose in the clinic due to its ability to increase the levels of glutathione (GSH). In the present study, the aim was to investigate the protective effects of NAC against CDDP-induced apoptosis in human-derived HepG2 cells. The results showed that upon exposure of the cells to CDDP, oxidative stress was significantly induced. DNA damage caused by CDDP was associated with cell apoptosis. NAC pre-treatment significantly reduced the malondialdehyde (MDA) levels and ameliorated the GSH modulation induced by CDDP. NAC also protected against DNA damage and cell apoptosis. These data suggest the protective role of NAC against hepatocyte apoptosis induced by CDDP was achieved through the inhibition of DNA damage and alterations of the redox status in human derived HepG2 cells. These results indicate that NAC administration may protect against CDDP-induced damage.

Normative measurements of extraocular musculature by multislice computed tomography.

Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice CT scanner. For each subject, one axial image at the central level of the eyeball, one coronal image about 1 cm behind globe, and two oblique sagittal images respectively along the left and right optic nerve were used for measurements of the thickness and width of EOMs. The statistic significance of measurement value between male and female and between left and right eyes was evaluated. Results There were no significant differences in the thickness and width of superior muscle group, lateral rectus, medial rectus, lateral rectus, superior oblique, inferior oblique and the thickness of levator palpebrae superioris between the left and right eyes as well as between male and female groups (all P>0.05). The thickness of superior muscle group and inferior rectus had not significant difference (2.9±0.7 vs. 3.3±0.8 mm, P=0.162), while the thickness of medial rectus was significantly higher than that of lateral rectus (3.1±0.5 vs. 2.2±0.6 mm, P=0.000). Conclusions The CT measurement of extraocular musculature is simple and time-saving and can be applied in the clinical work. The normative data obtained may be useful in determining pathologic enlargement of the EOMs in both thyroid-associated orbitopathy patients and other various orbital conditions.

[Study on preparation process of artesunate polylactic acid microspheres].

This study aims to investigate the preparation process and in vitro release behavior of artesunate polylactic acid microspheres, in order to prepare an artesunate polylactic acid (PLA) administration method suitable for hepatic arterial embolization. With PLA as the material and polyvinyl alcohol (PVA) as the emulsifier, O/W emulsion/solvent evaporation method was adopted to prepare artesunate polylactic acid microspheres, and optimize the preparation process. With drug loading capacity, encapsulation efficiency and particle size as indexes, a single factor analysis was made on PLA concentration, PVA concentration, drug loading ratio and stirring velocity. Through an orthogonal experiment, the optimal processing conditions were determined as follows: PLA concentration was 9. 0% , PVA concentration was 0. 9% , drug loading ratio was 1:2 and stirring velocity was 1 000 r x min(-1). According to the verification of the optimal process, microsphere size, drug loading and entrapment rate of artesunate polylactic acid microspheres were (101.7 +/- 0.37) microm, (30.8 +/- 0.84)%, (53.6 +/- 0.62)%, respectively. The results showed that the optimal process was so reasonable and stable that it could lay foundation for further studies.

Clinical application of magnetic resonance imaging in preoperative evaluation of endometrial cancer.

OBJECTIVE: To investigate the value of magnetic resonance imaging (MRI) in the preoperative assessment of endometrial cancer. METHODS: Ninety-four patients with histopathologically confirmed endometrial carcinoma were retrospectively enrolled in this study. MRI findings were compared with the pathologic findings in all cases. The depth of myometrial invasion and lymph node metastasis were evaluated by T2 weighted imaging (T2WI) combined with contrast enhancement or diffusion weighted imaging (DWI). RESULTS: Among these 94 patients,62 had no or superficial myometrial involvement and 32 cases had deep myometrial involvement. Meanwhile, 24 groups of metastatic lymph nodes and 164 groups of non-metastatic lymph nodes were detected. The accuracy, specificity, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in discriminating no/superficial myometrial involvement from deep myometrial involvement were 88.3%, 90.3%, 84.4%, 91.8%, and 81.8%, whereas those of T2WI combined with DWI were 81.9%, 87.1%, 71.9%, 85.7%, and 74.2%, respectively. The accuracy, specificity, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in identifying metastatic lymph nodes were 89.4%, 96.8%, 54.5%, 90.9%, and 78.3%, whereas those of T2WI combined with DWI were 91.5%, 95.5%, 72.7%, 94.3%, and 77.4%, respectively. CONCLUSIONS: T2WI combined with contrast enhancement is superior to T2WI combined with DWI in evaluation of the depth of myometrial invasion. However, DWI is more sensitive in identifying lymph node metastasis than T2WI combined with contrast enhancement.

Quantitative evaluation of extraocular muscle with high-field magnetic resonance in patients with Graves' ophthalmopathy with upper-lid retraction.

OBJECTIVE: To evaluate the feasibility of high-field magnetic resonance in measuring the thickness and width of extraocular muscles, calculate the ratio of thickness to width, and summarize the characters of the diameters and its ratio in patients with Graves' ophthalmopathy (GO) with upper-lid retraction. METHODS: Sixteen GO patients with upper-lid retraction (GO group) and 14 healthy control group were enrolled in this study. All the patients underwent enhanced high-field magnetic resonance orbital scan. The thickness and width of extraocular muscles were measured on axial, coronal or oblique sagittal enhanced T1 weighted images. The ratio of thickness to width (R1) and width to thickness (R2) were calculated. The diameters or ratio was evaluated as enlarged when they were 2 standard deviation greater than mean values of extraocular muscle in healthy control. RESULTS: The thickness of levator palpebrae superioris, medial rectus, and inferior rectus muscles in GO group were significantly larger than those in the control group (P=0.000, P=0.017, P=0.032, respectively. The width of superior oblique muscles in GO group was significantly larger than that in control group (P=0.000). The R1 values of levator palpebrae superioris, inferior rectus, medial rectus, and lateral rectus muscles in GO group were significant larger than those in the control group (P=0.000,P=0.037, P=0.019,P=0.032, respectively. The R2 value of superior oblique muscles was significant larger than that in the control group (P=0.027). Aslo in GO group, 32 extraocular muscles showed an increased thickness. 47% of thickened extraocular muscles had an increased R1. CONCLUSIONS: Enhanced orbit imaging with high-field magnetic resonance is helpful in the quantitative assessment of the thickness and width of extraocular muscles. In GO patients, in addition to the levator palpebrae superioris muscles, some other extraocular muscles also becomes thicker. Moreover, the increased diameters of superior oblique muscles is mainly due to the increase of its width R1 and R2 values can reflect the thickness and width of extraocular muscles and their relationship.

[Construction of a recombinant Lactobacillus acidophilus expressing high levels of Helicobacter pylori adhesin Hp0410].

OBJECTIVE: To construct a recombinant Lactobacillus acidophilus that expresses high levels of Helicobacter pylori (Hp) adhesin Hp0410. METHODS: The gene fragment encoding Hp0410 was amplified by PCR from the DNA of H. pylori NCTC11639 strain and cloned into the shuttle plasmid pMG36e to construct pMG36e-Hp0410, which was transformed into Lactobacillus acidophilus by electroporation. The target protein was confirmed with SDS-PAGE and silver nitrate staining and analyzed by Western blotting. The stability of the recombinant plasmid was assessed by drawing the growth curve of the recombinant Lactobacillus acidophilus. RESULTS: A 750-bp fragment was inserted into the pMG36e plasmid and transformed into Lactobacillus lactis. The transformed bacterium expressed the target protein with a relative molecular mass of about 34 kD. Western blotting confirmed that the expressed proteins could be recognized by the serum of patients with Hp infection. The recombinant plasmid pMG36e-Hp0410 exhibited good stability in the presence or absence of erythromycin. CONCLUSIONS: The recombinant Lactobacillus acidophilus with high constitutive expression of Hp0410 has been constructed successfully.

Optimization of trehalose production by a novel strain Brevibacterium sp. SY361.

Trehalose production by a novel strain of Brevibacterium sp. SY361 was optimized in submerged fermentation. Different chemical and physical parameters such as carbon and nitrogen sources, inoculum level, initial pH, incubation temperature, aeration and time-course of fermentation, were studied in order to increase trehalose productivity. An optimal production medium containing 3% (w/v) glucose, 0.9% (v/v) corn steep liquor, 0.5% (w/v) KH(2)PO(4) and 0.4% (w/v) MgSO(4).7 H(2)O was found suitable for trehalose production. An optimal volume of medium in a 500 ml flask was 80 ml. The optimal levels of other parameters were 4.0% (v/v) of inoculum, initial pH of 6.0, incubation temperature of 28-32 degrees C and time-course of 60 h. Optimized parameters gave a maximum trehalose of 12.2 mg/ml with a conversion rate of 58.4%.