https://faculty.washington.edu/renatab/courses/PSE490/downloads/pretreatment.pdf

Features of promising technologies for pretreatment of lignocellulosic biomass.

Improvement of enzyme activity, stability and selectivity via immobilization techniques

Phosphate solubilizing bacteria and their role in plant growth promotion

Laccases of fungi attract considerable attention due to their possible involvement in the transformation of a wide variety of phenolic compounds including the polymeric lignin and humic substances. So far, more than a 100 enzymes have been purified from fungal cultures and characterized in terms of their biochemical and catalytic properties. Most ligninolytic fungal species produce constitutively at least one laccase isoenzyme and laccases are also dominant among ligninolytic enzymes in the soil environment. The fact that they only require molecular oxygen for catalysis makes them suitable for biotechnological applications for the transformation or immobilization of xenobiotic compounds.

Fungal laccases - occurrence and properties.

Industrial applications of microbial lipases

The heavy metal-resistant bacterial community of strongly polluted industrial areas was investigated. The bacterial tolerance levels to nickel, chromium and copper depended greatly on the pollution degree of sampling sites. Thirty-six selected strains were tested on their multiple heavy metal resistance, most strains were resistant to high concentrations of nickel as well as of chromate. Remarkably, 4 plasmid-containing strains with an extreme resistance to nickel (up to 20 mM) were Gram-positive and identified as Arthrobacter spp. Nickel resistance is an induced mechanism in 3 strains and is constitutively expressed in one of the 4 strains; nickel resistance is influenced by temperature. This is the first description of extreme nickel resistance in Grampositive bacteria.

Bacterial heavy metal‐tolerance — extreme resistance to nickel in Arthrobacter spp. strains

A non-motile, rod-shaped, red-pigmented bacterium, designated strain BZ33rT, was isolated from soil of an industrial site. Cells stained Gram-negative and were aerobic and psychrophilic, showing good growth at 1–20 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BZ33rT was related to members of the genus Hymenobacter and had highest sequence similarity with Hymenobacter
aerophilus DSM 13606T (97.5 %). The predominant cellular fatty acids were anteiso-C15 : 0 (20.3 %), summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH; 20.2 %), iso-C15 : 0 (20.0 %), summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B; 8.2 %) and C16 : 1ω5c (7.9 %). Strain BZ33rT had MK-7 as the major menaquinone. The polyamine pattern contained sym-homospermidine as the major compound with moderate amounts of spermidine. Phosphatidylethanolamine, three unknown aminophospholipids, two unknown aminolipids, two unknown glycolipids and five unknown polar lipids were present in the polar lipid profile. The G+C content of the DNA was 61.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data, strain BZ33rT is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter psychrophilus sp. nov. is proposed. The type strain is BZ33rT ( = DSM 22290T  = CGMCC 1.8975T  = LMG 25548T).

Dyadobacter psychrophilus sp. nov., a psychrophilic bacterium isolated from soil

SUMMARY: Penicillium simplicissimum excreted more than 100 mmol citric acid l-1 [2-9 mmol (g dry wt)-1; 9 d] if an industrial filter dust (> 50 % ZnO) providing a high extracellular buffering capacity was present in the medium. A similar specific [2 mmol (g dry wt)-1], but lower absolute (26 mmol l-1), citric acid excretion occurred in the absence of an extracellular buffer and if amino acids or urea were used as nitrogen source. P. simplicissimum excreted no citric acid under conditions where Aspergillus niger produces citric acid (deficiency of trace elements, low pH and reduced biomass formation). Citric acid excretion by P. simplicissimum always paralleled biomass formation and occurred in a pH range between 4 and 7. This indicated that different imbalances of metabolism were responsible for citric acid excretion in A. niger and P. simplicissimum. However, provided a high extracellular buffering capacity was present, the response of the Penicillium system to different carbon and nitrogen sources was similar to the Aspergillus system. In contrast, the metals iron and copper had virtually no effect on citric acid excretion compared with A. niger. Estimation of intracellular citric acid, as well as the effects of the uncoupler 2,4-dinitrophenol, and the H+-ATPase inhibitor sodium orthovanadate, led to the conclusion that the buffer-stimulated citric acid efflux was dependent on metabolic energy and an energized plasma membrane, respectively. Despite similarities to the Aspergillus system, a different mechanism for buffer-stimulated citric acid excretion by P. simplicissimum seems probable.

/pdf/influence-of-medium-components-and-metabolic-inhibitors-on-4y1b09d09c.pdf

Influence of medium components and metabolic inhibitors on citric acid production by Penicillium simplicissimum.

A non-motile, rod-shaped, yellow bacterium, designated C16yT, was isolated from alpine glacier cryoconite. Cells behaved Gram-positively, were aerobic and psychrophilic (good growth at 1–25 °C). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain C16yT was related to the genus Sphingomonas and had highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082T (97.6 %) and Sphingomonas echinoides DSM 1805T (97.2 %). DNA–DNA hybridization demonstrated that strain C16yT could not be considered as a member of either Sphingomonas oligophenolica or Sphingomonas echinoides. Strain C16yT contained Q-10 as the predominant ubiquinone and C18 : 1 and C16 : 0 were the dominant fatty acids. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, five unidentified glycolipids, two unidentified aminophospholipids and two unidentified lipids. The major polyamines were the triamines sym-homospermidine and spermidine. The G+C content was 67.9 mol%. Combined data from phenotypic, phylogenetic and DNA–DNA relatedness studies demonstrated that strain C16yT is a representative of a novel species of the genus Sphingomonas, for which we propose the name Sphingomonas glacialis sp. nov. The type strain is C16yT (=DSM 22294T =CGMCC 1.8957T =CIP 110131T).

/pdf/sphingomonas-glacialis-sp-nov-a-psychrophilic-bacterium-17wfc13blq.pdf

Sphingomonas glacialis sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.

To determine the importance of Al-availability for soil micro-organisms 95 forest soils from Tyrol/Austria with comparable topography, vegetation, climatic conditions, soil type and with low soil pH (median = 3.9) were investigated for their physical (percentage of stable aggregates, water holding capacity), chemical (pH, electrical conductivity, contents of organic matter, concentrations of easily extractable aluminium, calcium, potassium, magnesium and phosphorus) and microbiological characteristics (microbial biomass and respiration, metabolic quotient, content of ATP, activities of protease and CM-cellulase, cfu-values of total and Al-tolerant bacteria and fungi). A highly significant negative correlation was detected between concentrations of KCl-extractable aluminium and soil pH. By the application of multivariate statistical methods, the effect of the concentration of KCl-extractable aluminium on abundance and activities of soil micro-organisms could be revealed. Al turned out to be of great importance for micro-organisms and often outmatched the significance of other well known soil properties like organic matter, pH or water holding capacity. However, due to very healthy trees at the sites under investigation no effect of Al or soil acidification on forest decline could be detected.

Franz Schinner

Papers

Bacterial heavy metal‐tolerance — extreme resistance to nickel in Arthrobacter spp. strains

Dyadobacter psychrophilus sp. nov., a psychrophilic bacterium isolated from soil

Influence of medium components and metabolic inhibitors on citric acid production by Penicillium simplicissimum.

Sphingomonas glacialis sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.

Microbiological Properties in Acidic Forest Soils with Special Consideration of KCl Extractable Al