Genome sequencing of Streptomyces aureofaciens DM-1 and analysis of 6-demethylchlortetracycline biosynthesis gene cluster / 生物工程学报

Streptomyces aureofaciens DM-1 is a high-yielding 6-demethylchlortetracycline producer. The genome sequencing of DM-1 reveals a linear chromosome containing 6 824 334 bps nucleotides with GC content of 72.6%. In this genome, a total of 6 431 open reading frames were predicted by using glimmer 3.02, Genemark and Z-Curve softwares. Twenty-eight secondary metabolite biosynthetic gene clusters were uncovered by using AntiSMASH gene prediction software, including the complete 6-demethylchlortetracycline biosynthetic gene cluster. A frame-shift mutation in methyltransferase coding region was detected, which may result in the demethylation of chlortetracycline. The complete genome sequence of S. aureofaciens DM-1 provides basic information for functional genomics studies and selection of high-yielding strains for 6-demethylchlortetracycline.

Methanogenic toxicity evaluation of chlortetracycline hydrochloride

Background Anaerobic digestion is a technology applied successfully to converting organic matter into biogas. However, the presence of inhibitory compounds such as antibiotics can adversely affect methane production. The aim of this study is to evaluate the toxic effect of chlortetracycline hydrochloride (CLOR) on the methanogenic bacteria. In order to study the methanogenic toxicity of CLOR, different concentrations of CLOR (10, 50, 100, 200 mg L- 1) were evaluated by methanogenic toxicity assays using three feedings. Results Maximum methane production was obtained for the assays with 10 mg CLOR L- 1, the values obtained were 277 ± 4.07; 193 ± 11.31 and 166 ± 7.07 mL for the first, second and third feedings, respectively. The average values for acetic, propionic and butyric acid at start of the experiments were 2104 ± 139; 632 ± 7.6; 544 ± 26 mg L- 1, respectively. The VFA values obtained finally of the experiment were dependent on the evaluated antibiotic concentrations, indicating that the efficiency of methanogenesis is directly affected by the CLOR concentration. Conclusions CLOR is an effective methanogenic bacteria inhibitor. Moreover, the results show that CLOR has a bactericidal effect on methanogenic activity given that methane production did not recover during the third feeding. This study shows that the 50% inhibitory concentration (IC50) for methanogenic bacteria in 10 mg L- 1.

Effectiveness of prebiotic as an alternative to the antimicrobial growth promoter on growth performance, blood constituents, intestinal healthiness and immunity of broilers

This study was designed to compare the effect of the prebiotic and antimicrobial growth promoter [AGP] on the growth performance, blood constituents, intestinal bacteriology and histomorphometric parameters as well as humeral immunity of broiler chicks. A total of 90 unsexed commercial Cobb chicks were randomly assigned to 3 dietary treatments [control, AGP and prebiotic groups], each group contains 30 chicks. Each group subdivided into 3 replicates, 10 chicks each, and was reared for 42 days. The prebiotic supplemented group showed a significant improvement in growth performance parameters in comparison to the control and AGP-supplemented groups. Total leukcocytic count, lymphocyte percent, total protein, total globulin and gamma globulin were significantly increased in the broilers fed on prebiotics. Moreover, prebiotics supplementation significantly reduced heterophil percent, heterophil/ lymphocyte ratio [H/L ratio], albumin/globulin ratio, aspartate and alanine aminotransferase [AST and ALT], uric acid and creatinine compared to the AGP-supplemented and control groups. The AGP-supplemented group exhibited a significant reduction in the total aerobic count when compared to the control and prebiotic-supplemented groups. However, the prebiotic supplemented group showed a significant reduction in the coliform count when compared to the control and antibiotic supplemented groups. The prebiotic supplemented group induced a significant increase in the villus height [VH] all over the small intestine. In addition, it induced a significant increase in villus height: crypt depth ratio in the duodenum and jejunum in comparison to the control and antibiotic supplemented groups. However, there were no significant differences among the different groups regard to the crypt depth [CD] in the duodenum and jejunum. Prebiotics could be considered as safe and effective antimicrobial alternatives for broiler chicks' growth performance, immunity and intestinal bacteriology and morphology

Effect of heparin on in vitro capacitation of boar sperm

Chlortetracycline (CTC) fluorescent pattern, the ability to undergo acrosome reaction (AR) upon exposure to 10 µM calcium ionophore A23187 and vitality estimation were used to investigate the effect of the sulfated glycosaminoglycan heparin on the in vitro capacitation of porcine spermatozoa. Sperm incubation in capacitating medium (CM) supplemented with 10 mM heparin for up to 120 min, showed an increase in the number of capacitated sperm (B pattern) and acrosome reacted sperm (AR pattern), without affecting their viability. In this condition, spermatozoa were incubated in CM depleted of albumin, calcium, bicarbonate or combinations, in the presence of heparin. In either calcium or bicarbonate-free media, capacitation was only basal and did not show variations in the presence of heparin. In absence of albumin the presence of calcium and bicarbonate stimulated capacitation, which was further increased by the addition of heparin. These results suggest that heparin enhances in vitro capacitation of porcine sperm only under capacitating conditions. Additionally, when sperm were incubated with 100 µg/ml biotinylated heparin in the presence or absence of unlabeled heparin, we observed that heparin binding sites were located mostly on the acrosomal region of boar sperm in an specific and saturable manner. The in vitro effect of heparin described in this work indicates that sulfated glycosaminoglycans, which are normally present in the female reproductive tract, might play an important role in the fertilization process in porcines.

Comparison of three methods for evaluating acrosome reaction in human spermatozoa / 中华男科学杂志

<p><b>OBJECTIVE</b>To find a convenient and exact method for evaluating acrosome reaction in human spermatozoa.</p><p><b>METHODS</b>The semen of the normal male was mixed and then divided into 6 groups. Coomassie brilliant blue (CBB) staining, chlortetracycline (CTC) fluorescence staining and acid phosphatase (ACP) detection were used for morphological observation and data analysis of the acrosome status of the human sperm treated with or without progesterone.</p><p><b>RESULTS</b>There were obvious morphological differences between the acrosome-reaction and acrosome-intact spermatozoa in CBB staining and CTC fluorescence staining, and significant differences were observed between the experimental and control spermatozoa by the three methods (P < 0.05).</p><p><b>CONCLUSION</b>All the three methods can be used to assess acrosome reaction in human spermatozoa, but Coomassie brilliant blue (CBB) staining is much more convenient and stable.</p>

Proacrosin-acrosin activity in capacitated and acrosome reacted sperm from cryopreserved bovine semen

Acrosin activity is associated with normal fertility in human and bovine spermatozoa. The aim of the study was to determine the variation of the enzyme activity in the proacrosin-acrosin system in capacitated and acrosome recated cryopreserved bovine sperm. Enzyme activity was assessed spectrophotometrically using N-alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA) as specific substrate for acrosin at pH 8. Capacitation with heparin and quercitin failed to induce conversion of proacrosin to acrosin. An increase in acrosin activity produced by the presence of progesterone, in a dose-dependent manner, was related with the induction of true acrosome reaction. The total level of acrosin activity registered showed that 96 per cent of acrosin of capacitated sperm samples and control is present in the zymogen form. Moreover, progesterone is capable of duplicating the level of active enzyme, indicating that enzyme activity changes are related to acrosome reaction, suggesting that only a minor proportion of the total of proacrosin-acrosin system is required in the exocytotic process on cryopreserved bovine sperm.

Application of element and metabolism balancing for the cultivation process with Streptomyces aureofaciens / 生物工程学报

On the base of element and metablism balancing, the mathematical model of the cultivation process with Streptomyces aureofaciens was developed, and the unknown parameters in the model were estimated with the method of nonlinear optimization. Firstly the energetic coefficient of CTC biosynthesis was gained, which was 1.8 - 2.8 mol-ATP x C-mol(-1). The macroscopic reaction rates were predicted in the process and compared with the experimental values. The results show that the model can preferably describe the relationships between several macroscopic reaction rates in the process and can supervise the optimization of CTC fermentation process theoretically.

Effect of Fertilization Promoting Peptide on Kinematic Parameters, Capacitaion and Acrosome Reaction in Human Spermatozoa / 대한불임학회지

OBJECTIVE: This study has been carried out to evaluation the effect of fertilization promoting peptide (FPP) on the kinematic parameters, capacitation and acrosome reaction of the frozen-thawed human spermatozoa. METHODS: After FPP treatment, we examined kinematic parameters, capacitation and acrosome reaction, using the methods of computer-aided sperm analysis (CASA) and chlortetracycline (CTC) fluorescence analysis. RESULTS: We have obtained the evidence that FPP can promote the capacitation and inhibit the spontaneous acrosome reaction of frozen-thawed human spermatozoa in vitro. Fpp (25~100 nM) induced a significant increase in the proportion of B-pattern capacitated spermatozoa, and a significant decrease in the proportion of F-pattern uncapacitated ones without significant stimulation of acrosomal exocytosis. In the kinematic parameters treatment, FPP treated groups maintained higher LIN, BCF and STR than those of control. The VAP, VSL, VCL and ALH were not different. Therefore it is suggested that FPP in human seminal plasma may play a positive role in promoting human sperm function.

Ca2+-ATPase Role in the Capacitation and Acrosome Reaction Assessed by a Chlortetracycline Fluorescence Assay / 대한불임학회지

It has been reported that the Ca2+-ATPase and the Ca2+-Na+exchanger play an important role for the regulation of intracellular Ca2+ in somatic cells, the Ca2+-ATPase located in the plasma membrane helps the Ca2+ concentration in maintain low [Ca2+]i. Roldan & Fleming reported that the spermatozoan Ca2+-ATPase plays an important role in the capacitation and acrosome reaction. We used to assess Ca2+ changes by chlortetracycline (CTC) patterns in the capacitation and acrosome reaction of human and hamster spermatozoa. In the present study applying quercetin which has been known as an ATPase antagonist, the enzymatic effect of Ca2+-ATPase on capacitation and acrosome reaction was found to be remarkable: a significant increase of the transformation from the original type to the B type and the AR type of spermatozoa. This finding suggests that Ca2+-ATPase play an important role in the efflux and the influx of the Ca2+ which have been known to be an essential factor for the capacitation and acrosome reaction, and that the inhibitory action of the Ca2+-ATPase might be a prerequsit step toward the capacitation and acrosome reaction. In conclusion, this study suggest the considerable evidence as follows: the increment of the intracellular Ca2+ concentration occurred by controlling the slope of Ca2+ concentration through Ca2+-ATPase activites in both the intracellular and extracellulr fluid may be important procedures for the capacitation and the acrosome reaction, and finally for fertilization of the sperm and ovum.

Clinical Observation on Pyodermas / 대한피부과학회지

Clinical observations were made on 251 cases of pyodermas at the Department of Dermatology, Kyungpook University Hospital from 1968 to 1972. Especially noteworthy is the application of josamycin to 41 cases of pyodermas to observe its therapeutic effects. Since 1968, the frequency of pyodermas has shown an annual increase. The ratio between male and female was 1. 4: 1, gradually changing from 2. 3: 1 in 1968 to an almost balanced incidence in 1972. The age of onset. differed with types of disease, but 76. 2% of all cases occurred before the age of 15. The outbreaks of impetigo bullosa and impetigo vulgaris were found to be affected by season, the highest prevalence being in summer. Seasonal occurrence of all cases was found to be 45.5% in summer and 24. 3% in fall with no noticeable change ohserved in spring and winter. Predilection sites of the disease differed according to the type of the disease but all types showed a marked predilection for the exposed areas as against the covered areas (4 times). Sensitivity of causative organisms to antibiotics was found to be fairly high to cloxacillin, novobiocin and ampicillin, and relative to kanamycin, streptomycin and doxycycline but all tested cases showed resistance to tetracycline, chlortetracycline and oxytetracycline. Josamycin was effective in all types of pyodermas, and was dramtical]y so in impetigo bullosa of which pustules disappeared within 3 or 5 days of treatment. Two out of 41 cases complained of abdominal pain and weakness. The sensitivity of the causative organisms of all types of pyodermas to josamycin was 83. 3%.