Softwood biodegradation by an ascomycete Chrysonilia sitophila (TFB 27441 strain)

Biodegradation of softwood ( Pinus radiata ) by the ascomycete Chrysonilia sitophila was dependent on the nitrogen and glucose concentrations in the culture medium. Optimization studies of the delignification process, in which the nitrogen (0–50mmol/l NH⁺₄) and glucose (0–2%) concentrations were varied, showed a maximal value of 17·8% for sawdust degradation in cultures containing 10 mmol/l NH₄⁺and 1·0% glucose. Solubility of the decayed sawdust in 1% NaOH at maximal delignification conditions showed a threefold increase and changes in the thermogravimetric pattern were also observed. Biodegraded wood chips showed significant decreases of the 280 and 310 nm characteristic lignin bands in the u.v. reflectance spectra.     

Inhibition of germination and sporulation (conidiation) in Neurospora sitophila Shear & Dodge by carbon dioxide

A complete inhibition of germination and conidiation was observed inNeurospora sitophila when maintained under a pure carbon dioxide atmosphere. Experiments were performed to explain the relatively poor conidiation of this species of mold under standard laboratory experimental conditions.     

一株AEC^hrL—赖氨酸产生菌

从乳糖发酵短杆菌Brevibacterium Lactofermentum2645菌株出发选育L-赖氨酸产生菌,经分离复壮后,用硫酸二乙酯(DES)诱变处理,由添加S-(2-氨基乙基)—L—半胱氨酸(AEC)和L-苏氨酸的药物平板定向筛选,最后获得了一株L—赖氨酸高产菌E_(16-2)(AHV~(hr)SAM~gAEC~(hr))。进而通过正交试验、工艺条件试验最终获得了该菌株的最佳发酵条件,并考查了在此条件下的L-赖氨酸发酵过程,结果表明该菌具有生长、耗糖、产酸速度快、发酵周期短的明显特点。     

A new diabetic strain of rat (WBN/Kob)

A new, spontaneously occurring diabetic syndrome has been observed in the aged males of an inbred strain of Wistar rats, WBN/Kob. The main clinical sign, glycosuria, was first detected at about 60 weeks of age, and thereafter some animals developed hyperlipidaemia and gradual emaciation. Prior to the onset of glucosuria, male rats showed impaired glucose tolerance after a glucose load at 21 weeks of age. The histopathologic lesions of the pancreas in the diabetic males consisted of multifocal fibrosis, decreased in number and size of islets and atrophy of exocrine tissue. Multifocal inflammatory foci of varying stages were the main pancreatic lesion in prediabetic male rats. This inflammatory change was detected even in 12-week-old rats and tended to occur around the islets. Therefore focal fibrosis and the decrease in the number and size of islets were considered to result from post-inflammatory scarring. The maturity-onset of this syndrome and the impaired glucose tolerance in younger animals suggested that diabetes mellitus of this rat strain is insulin-independent type II. However, the histological lesions of the pancreas were somewhat different from previous reports of both type I and II diabetes mellitus in man and animals.     

Lignin degradation during softwood decaying by the ascomyceteChrysonilia sitophila

SoftwoodPinus radiata was degraded by the ascomyceteChrysonilia sitophila during 3 months. The total weight loss of the wood was 20% and the carbohydrate and lignin losses were 18% and 25%, respectively. Decayed wood was extracted with solvents of increasing polarity. Methanol and dioxane yielded extracts containing representative low molecular weight degraded lignins. The overall structure of the degraded lignins, as shown by U.V./visible, I.R.,¹H and¹³C NMR spectroscopy, GPC, functional group and elemental analyses, was compared with the structure of milled wood lignin extracted from undecayedP. radiata. The compilation of the data allows us to suggest oxidative C-C and -O-aryl cleavages for the mechanism of lignin degradation by this ascomycete. New saturated carbons on the side chain of the degraded lignins were detected. Based on these data a reductive ability of this microorganism was also suggested.     

A strain producing abundant brachypterous adults in Nilaparvata lugens (Homoptera: Delphacidae)

Compared with adults from a wild strain, phenotypically normal-eyed heterozygotes from a stock culture of the red-eyed (r/r) recessive mutation strain were confirmed to produce brachypterous progeny relatively more abundantly. The wing character has been shown not to be linked with the r gene, but the association that has developed between them may perhaps be the result of culture methods which have uncosciously selected the offspring of brachypterous females for many generations.

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Zusammenfassung Phänotypisch normaläugige Heterozygote einer Stammzucht der rotäugigen (r/r) rezessiven Mutanten erzeugten zu höherem Prozentsatz brachyptere Nachkommen als ein Wildstamm. Der Flügelcharakter erwies sich an sich als nicht verbunden mit dem r-Gen; jedoch mag die Beziehung, die sich hier ergab, verursacht sein durch die Zuchtmethoden, durch die unbewusst in Verlauf vieler Generationen Nackommen der kurzflügeligen Weibchen selektiert wurden.

     

A new obesity-prone,glucose-intolerant rat strain (F.DIO)

Previous breeding for the diet-induced obese (DIO) trait from outbred Sprague-Dawley rats produced a substrain with selection characteristics suggesting a polygenic mode of inheritance. To assess this issue further, selectively bred DIO male rats were crossed with obesity-resistant inbred Fischer F344 dams. Male offspring were crossed twice more against female F344 dams. The resultant N3 (F.DIO) rats were then inbred three more times. On low-fat chow, 10-wk-old male and female DIO rats weighed 86 and 59% more than respective F344 rats. By the N3 (F.DIO) generation, they were only 12 and 10% heavier, respectively. After three additional inbreeding cycles, chow-fed F.DIO males had an exaggerated insulin response to oral glucose compared with F344 rats. After 3 wk on a 31% fat (high-energy) diet, male N3 F.DIO rats gained 16-20% more carcass and adipose weight with 98% higher plasma leptin levels, whereas F.DIO females gained 36-54% more carcass and adipose weight with 130% higher leptin levels than comparable F344 rats. After three inbreeding cycles, F.DIO males still gained more weight on high-energy diet and developed a threefold greater insulin response to oral glucose than F344 males. Preservation of the DIO and glucose intolerance traits through successive backcrosses and inbreeding cycles to produce the F.DIO strain lends further support to the idea that they inherited in a polygenic fashion.     

A mutant strain of Chymomyza costata (Diptera: Drosophilidae) insensitive to diapause-inducing action of photoperiod

ABSTRACT. From a Japanese population of Chymomyza costata which has been known to have a photoperiodic larval diapause, we selected a mutant strain which did not respond to photoperiod. However, about 70% of the individuals of this strain entered diapause at 11^oC irrespective of photoperiod, and about the same percentage of those of the photoperiod-sensitive strain also did so in continuous illumination at 11^oC. This indicates that low temperature induces diapause independently of photoperiod. On the other hand, a temperature drop from 18 or 25^oC to 15^oC and chilling at 4^oC did not induce diapause.     

Specificity of a strain ofNeozygites sp. (Zygomycetes: Entomophthorales) toMononychellus tanajoa (Acari: Tetranychidae)

Neozygites sp. is commonly found infecting the cassava green mite,Mononychellus tanajoa (Bondar), in parts of northeast Brazil. The introduction of this fungus into other regions requires the knowledge of its specificity, especially in relation to natural enemies of different cassava pests. Laboratory tests indicated the development of germination tubes ofNeozygites in some females ofTetranychus bastosi Tuttle et al. andT. urticae Koch, with subsequent formation of a reduced number of hyphal bodies in someT. bastosi. No females of the phytoseiid predatorsAmblyseius idaeus (Denmark & Muma) andAmblyseius limonicus Garman & McGregor s.l. were infected byNeozygites sp.     

A soluble NADH dehydrogenase (NADH: ferricyanide oxidoreductase) from Thermus aquaticus strain T351.

A soluble NADH dehydrogenase (NADH:ferricyanide oxidoreductase) has been obtained by simple disruption of cells of Thermus aquaticus strain T351, and purified. The enzyme is of low molecular mass, 50 000 Da, and displays many of the properties of the membrane-bound enzyme, including inhibition by both NADH and ferricyanide, and the same Km for ferricyanide. The enzyme contains 0.05 mol of FMN, 0.16 mol of labile sulphur and 2.2 mol of iron per mol of protein. The enzyme is inhibited by NAD and cupferron competitively with ferricyanide, and by ATP (but not ADP) competitively with NADH. The enzyme is particularly thermostable, having a half-life at 95 degrees C of 35 min. The effect of temperature on the molar absorption coefficient and the stability of NADH was determined.     

A thermo-stable dehalogenase in the extracts fromPseudomonas sp (strain 19S)

Summary A thermo-stable dehalogenase was demonstrated in the crude extracts fromPseudomonas sp (19S). The ability of the enzyme to catalyze the dehalogenation of various halogen-substituted organic acids was investigated and the highest activity was found with monochloroacetate. The enzyme followed Michaelis-Menten kinetics, and the K_m for monochloroacetate was 0.2mM. Maximum activity was found at pH 10.5 and 60°C. The enzyme activity in the cell-free extract was unaffected by EDTA or by Mn, Zn, or Cu ions, but was dramatically reduced by HgCl₂ (70%) and Pb (NO₃)₂ (80%).     

以小鼠检测鸡霍乱G190E_（40）疫苗的效力试验

为检测鸡霍乱Ｇ１９０Ｅ４０疫苗,以该苗的不同剂量接种小鼠,测出其最小免疫量和安全性。并以同法对鸡进行平行试验。之后分别以Ｃ４８—１强毒的最小致死量攻击。比较此法对两种动物的差异。试验结果表明,用小鼠替代鸡检测鸡霍乱苗,即安全,又可降低检测成本,因此本法具有实际应用价值。