Microbiota of the Kinderlinskaya cave (South Urals,Russia)

The mesophilic and psychrotolerant microbiota of the air, soil, water, and bottom sediments of the Kinderlinskaya cave (South Urals, Russia) and the factors affecting the structure of microbial communities were investigated. The pattern of microbial distribution in soils was shown to depend on both the configuration of the cave and the level of recreational load. The lowest numbers of bacteria and micromycetes were found in the poorly visited, difficult-to-access sites. Coliform bacteria were revealed in all soil and sediment samples and in some water samples. Micromycetes belonged to 19 genera, with Geomyces pannorum as the dominant species. Air movement was shown to be the main factor affecting the density of the aerial microbiota.     

Involvement of Boiling Stable Antioxidant Enzymes in Adaptation of Invasive Alien Plant Lantana to Abiotic Stress under Natural Conditions

Russian Journal of Plant Physiology - Lantana camara L. is noxious weed affecting ecosystem and biodiversity worldwide. However, the biochemical basis of invasiveness and adaptation to abiotic...     

Molecular Modeling of Disease Causing Mutations in Domain C1 of cMyBP-C

Cardiac myosin binding protein-C (cMyBP-C) is a multi-domain (C0–C10) protein that regulates heart muscle contraction through interaction with myosin, actin and other sarcomeric proteins. Several mutations of this protein cause familial hypertrophic cardiomyopathy (HCM). Domain C1 of cMyBP-C plays a central role in protein interactions with actin and myosin. Here, we studied structure-function relationship of three disease causing mutations, Arg177His, Ala216Thr and Glu258Lys of the domain C1 using computational biology techniques with its available X-ray crystal structure. The results suggest that each mutation could affect structural properties of the domain C1, and hence it’s structural integrity through modifying intra-molecular arrangements in a distinct mode. The mutations also change surface charge distributions, which could impact the binding of C1 with other sarcomeric proteins thereby affecting contractile function. These structural consequences of the C1 mutants could be valuable to understand the molecular mechanisms for the disease.     

A New Species of the Genus Colilodion Besuchet (Coleoptera: Staphylinidae: Pselaphinae) from Vietnam

A new pselaphine species, Colilodion thienmu n. sp., is described from Mt. Bach Ma in Central Vietnam. SEM photographs of this species are provided and morphological notes are given in this study.     

Hydrocarbon biodegradation and surfactant production by acidophilic mycobacteria

Production of biosurfactants by acidophilic mycobacteria was demonstrated in the course of aerobic degradation of hydrocarbons (n-tridecane, n-tricosane, n-hexacosane, model mixtures of С₁₄–С₁₇, С₁₂?С₁₉, and С₉–С₂₁n-alkanes, 2,2,4,4,6,8,8-heptamethylnonane, squalane, and butylcyclohexane) and their complex mixtures (hydrocarbon gas condensate, kerosene, black oil, and paraffin oil) under extremely acidic conditions (pH 2.5). When grown on hydrocarbons, the studied bacterial culture AG_S10 caused a decrease in the surface and interfacial tension of the solutions (to the lowest observed values of 26.0 and 1.3 mN/m, respectively) compared to the bacteria-free control. The rheological characteristics of the culture changed only when mycobacteria were grown on hydrocarbons. Neither the medium nor the cell-free culture liquid had the surfactant activity, which indicated formation of an endotype biosurfactant by mycobacteria. Biodegradation of n-alkanes was accompanied by an increase in cell numbers, surfactant production, and changes in the hydrophobicity of bacterial cell surface and in associated phenomena of adsorption and desorption to the hydrocarbon phase. Research on AGS10 culture liquids containing the raw biosurfactant demonstrated the preservation of its activity within a broad range of pH, temperature, and salinity.     

Effect of low-energy microwaves on DNA stability in solution

DNA isolated from liver of healthy and tumor-bearing (sarcoma 45) rats was irradiated in water-salt solution with weak microwaves (64.5 GHz, 50 μW/cm²). The heat stability of DNA increased with irradiation time (a raise of 1.5°C in T _m for “tumor” DNA after 90 min, without changes in ΔT), which may be associated with dehydration of the surrounding Na⁺ ions.     

Lysozyme activity in the leukocytes and blood serum of white rats administered massive doses of penicillin preparations]

Activity of lysozyme in the blood serum and leucocytes was determined. The experiments were carried out on albino unbred rats weighing 170 to 200 gm. Benzylpenicillin and oxacillin were administered intramuscularly in doses of 500000 Units/kg or 20000 gamma/kg once every 24 hours for 2, 4 and 6 days. The activity of lysozyme was determined by the turbidimetric and agar-diffusion methods. It was found that the activity of lysozyme in the leucocytes increased by the 5th day accompanied by a simultaneous decrease in its level in the serum followed by reaching the initial values. The data are indicative of the fact that the use of antibiotics in mega-doses is not contraindicated from the point of view of their effect on lysozyme activity.     

Electrophysiological and Pharmacological Analysis of Neuronal Activity in the Midbrain Medial Raphe Nucleus after Acute Immobilization Stress

In albino rats anesthetized with urethane, most medial raphe neurons are characterized by a low rate of the discharges. Acute immobilization stress resulted in a significant enhancement in the number of regularly discharging neurons. After immobilization, the number of neurons with a low-rate impulsation decreased, while the number of neurons with intensive firing increased. Treatment with fluoxetine enhanced the number of regularly firing neurons more than three times, and a predominant part of the neurons demonstrated a high level of background activity. It should be supposed that a significant part of the neurons with high-rate discharges are serotonergic, because their number also increased after fluoxetine administration.