Fungal decomposition of oat straw during liquid and solid state fermentation

White rot fungi (Coriolus hirsutus, Coriolus zonatus, and Cerrena maxima from the collection of the Komarov Botanical Institute of the Russian Academy of Sciences) and filamentous fungi (Mycelia sterilia INBI 2-26 and Trichoderma reesei 6/16) were grown on oat straw-based liquid and solid media, as well as in a bench-scale reactor, either individually or as co-cultures. All fungi grew well on solid agar medium supplemented with powdered oat straw as the sole carbon source. Under these conditions, the mould Trichoderma reesei fully suppressed the growth of all basidiomycetes studied; conversely, Mycelia sterilia neither affected the development of any of the cultures, nor did it show any substantial susceptibility to suppression by their presence. Pure solid cultures of basidiomycetes, as well as the co-culture of Coriolus hirsutus and Cerrena maxima caused a notable bleaching of the oat straw during its consumption. When grown on the surface of oat straw-based liquid medium, the basidiomycetes consumed up to 40% polysaccharides without measurable lignin degradation (a concomitant process). Under these conditions, Mycelia sterilia decomposed no more than 25% lignin in 60 days, but this was observed only after polysaccharide exhaustion and biomass accumulation. In contrast, during solid state straw fermentation, white rot fungi consumed up to 75% cellulose and 55% lignin in 83 days (C. zonarus), whereas the corresponding consumption levels for co-cultures of Mycelia sterilia and Trichoderma reesei equaled 70 and 45%, respectively (total loss of dry weight ranged from 55 to 60%). Carbon dioxide-monitored solid-state fermentation of oat straw by the co-culture of filamentous fungi was successfully performed in an aerated bench-scale reactor.     

Theoretical study of enantiodifferentiation in solid state cyclodextrins

A molecular mechanics investigation of R- vs. S-phenylethanol, R- vs. S-mandelic acid, R- vs. S-flurbiprofen, and R- vs. S-fenoprofen in their cyclodextrin crystal environments was undertaken. It was found that the dominant force responsible for guesthost complexation is the short-range London force; the enantiodiscriminating forces tend to be very small and are generally, but not always, dominated by long-range electrostatic contributions. Derivatized cyclodextrins are generally more enantiodiscriminating than native cyclodextrins, perhaps due to exterior rather than interior guest-host binding. © 1993 Wiley-Liss, Inc.     

Xylanase production by Ganoderma lucidum on liquid and solid state fermentation

Ganoderma lucidum, a white rot fungus, was exploited for its potentials to produce xylanase employing shake and solid-state culture conditions. Different culture conditions such as pH, temperature, carbon and nitrogen requirements for its growth and production of xylanase were optimized. The culture media pH 6.0-7.0 and temperatures 30 degrees-35 degrees C significantly promoted the growth as well as xylanase secretion into the media. Xylan and peptone were found to be the suitable carbon and nitrogen sources. Among the different agrowastes used, wheat bran was found to be the best substrate for the test fungus for the production of xylanase than sugarcane bagasse and rice bran in solid-state fermentation.     

Comparison of solid and solution state protein structures. Photoacoustic study of solid state bovine methemoglobin derivatives

In an effort to examine the consequences of phase state changes on protein structures, optical absorption spectra of several bovine hemoglobin derivatives in lyophilized, ammonium sulfate-precipitated, and crystalline states were examined. Absorption spectra were used to compare protein conformations. Differences between solution and several solid state spectra were apparent. They were greatest for lyophilized preparations, were inhibited by ligand binding, the tightest binding ligand being the most effective inhibitor, and were substantially or totally reversible upon dissolving the solid state protein. Though the magnitude of spectral changes varied, they all indicated characteristically different proportions of the protein were converted to a reversible hemichrome in each type of solid state preparation. The extent of hemichrome formation was correlated with the degree to which the protein tends to be dehydrated in each solid state preparation. This may reflect the role of water in determining the three-dimensional structure of hemoglobin. Absorption spectra of solid state hemoglobin preparations were obtained from photoacoustic spectra using a novel method for spectral analysis. Results presented here demonstrate the utility of this procedure in probing structures of solid state proteins.     

Advantages of fungal enzyme production in solid state over liquid fermentation systems

The present paper attempts to explain why enzyme production in solid-state fermentation (SSF) is higher than in submerged fermentation (SmF). Recent work done in our laboratory [Biotechnol. Lett. 22 (2000) 1255; J. Ind. Microbiol. Biotechnol. 26 (5) (2001) 271; J. Ind. Microbiol. Biotechnol. 26 (5) (2001) 296] related to the production of invertase, pectinases and tannases, by Aspergillus niger grown by SSF and SmF is reviewed. To do such a comparative study, logistic and Luedeking–Piret equations are used in order to estimate the values of the following coefficients: maximal specific growth rate (μ_M), maximal biomass level (X_M), enzyme/biomass yield (Y_P/X) and secondary rate of production, or breakdown (k). It is shown that enzyme productivity is proportional to group, μ_MY_P/XX_M, corrected by a function of ν=k/Y_P/Xμ_M. In all three cases of enzyme production studied, productivity using a SSF system was higher than in SmF. Studies with invertase resulted in higher values of μ_MX_M. Studies with pectinases resulted in higher values of Y_P/XX_M. Studies with tannases resulted in higher Y_P/X and less negative values of k. Finally, a reaction–diffusion model is presented to try to explain such differences based on micrographic measurements of mycelial aggregates for each kind of fermentation system.     

Collagen functionalized with unsaturated cyclic anhydrides—interactions in solution and solid state

Maleic anhydride (CMA) and itaconic anhydride modified collagen (CITA) were prepared as precursors for production of interpenetrated polymer networks (IPN). Calculated values for Huggins coefficient in aqueous diluted and semi‐diluted solutions of modified collagen indicated a slightly tendency of aggregation for itaconic anhydride‐modified collagen. In semi‐diluted solution collagen (Coll) and CMA present slightly differences in the thixotropic behavior, while CITA has a pronounced thixotropic behavior. Flow and oscillatory measurements revealed an elastic behavior of the collagen solutions, pure and modified with MA or ITA, as the storage modulus (G′) has always a superior value compared with the loss modulus (G″). The denaturation temperature (T_d) of unmodified collagen increased from 34^oC to 40^oC for CMA and to 39^oC for CITA respectively, by formation of covalent bonds that stabilize the triple helix. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 228–236, 2014.     

13C-NMR study of 4-azasteroids in solution and solid state

A group of biologically active 4-azasteroids was studied by 13C-NMR spectroscopy in solution and in the solid phase. A full assignment of signals in the spectra of samples in chloroform was performed for thirteen 4-azasteroids using two-dimensional techniques. Substituent and steric effects of a nitrogen atom, and their influence on chemical shifts of the neighboring carbon atoms are discussed. CP MAS spectra were obtained for five 4-azasteroids including finasteride. The spectra confirmed polymorphism of the latter compound. In addition to the polymorphic forms that are already known, a new molecular complex of finasteride with dioxane is reported.     

Electrostatic interactions in the denatured state and in the transition state for protein folding: effects of denatured state interactions on the analysis of transition state structure

The development of electrostatic interactions during the folding of the N-terminal domain of the ribosomal protein L9 (NTL9) is investigated by pH-dependent rate equilibrium free energy relationships. We show that Asp8, among six acidic residues, is involved in non-native, electrostatic interactions with K12 in the transition state for folding as well as in the denatured state. The perturbed native state pK(a) of D8 (pK(a) = 3.0) appears to be maintained through non-native interactions in both the transition state and the denatured state. Mutational effects on the stability of the transition state for protein (un)folding are often analyzed in respect to change in ground states. Thus, the interpretation of transition state analysis critically depends on an understanding of mutational effects on both the native and denatured state. Increasing evidence for structurally biased denatured states under physiological conditions raises concerns about possible denatured state effects on folding studies. We show that the structural interpretation of transition state analysis can be altered dramatically by denatured state effects.     

Prebiotic peptide-formation in the solid state

The reactions of benzoate ion and of glycine with adenosine 5-phosphorimidazolide have been investigated. Benzoate reacts first to give the anhydride, benzoyl-adenylate, which, in the presence of excess imidazole, reacts further to give the 2'- and 3'-esters of adenosine 5'-phosphate. Glycine also first attacks the imidazolide to give an anhydride, but this compound may react further either to give 2- and 3'-esters or to form peptides, depending on the reaction conditions.     

Prebiotic peptide-formation in the solid state

When a solution containing gly-N-pa and imidazole is evaporated to dryness and then maintained at a temperature between 65 degrees C and 100 degrees C, high yields of AppA and obligoglycines are obtained. We believe that ImpA is formed first, and then activates the carboxyl group of glycine or gly-A-pA. If glycine, ATP or AppA, and imidazole are heated together in the solid state, ImpA is formed and ATP , or indirectly from imidazole and gly-N-pA. Next the carboxyl group or glycine is activated by the ImpA formed in situ. The subsequent reactions of activated glycine leads to the formation of oligoglycines and the 2' (3')-glycylester of pA. Under plausible prebiobic conditions, good yields of oligoglycines up to the octamer can be obtained from glycine, ATP and imidazole.     

Prebiotic peptide-formation in the solid state

The reactions of glycine with inorganic polyphosphates in the solid state have been studied. The formation of peptides up to the decamer occurs at moderate temperatures(r.t.-100 degrees C) in the presence of imidazole and magnesium chloride. If adenosine 5' -monophosphate is added to the reaction mixture, 2'(3') -o-glycyl adenosine 5'-monophosphate is also obtained. These reactions could have occurred on the primitive earth.     

"Zero-length" cross-linking in solid state as an approach for analysis of protein-protein interactions

We have developed a new approach for the analysis of interacting interfaces in protein complexes and protein quaternary structure based on cross-linking in the solid state. Protein complexes are freeze-dried under vacuum, and cross-links are introduced in the solid phase by dehydrating the protein in a nonaqueous solvent creating peptide bonds between amino and carboxyl groups of the interacting peptides. Cross-linked proteins are digested into peptides with trypsin in both H2(16)O and H(2)18O and then readily distinguished in mass spectra by characteristic 8 atomic mass unit (amu) shifts reflecting incorporation of two 18O atoms into each C terminus of proteolytic peptides. Computer analysis of mass spectrometry (MS) and MS/MS data is used to identify the cross-linked peptides. We demonstrated specificity and reproducibility of our method by cross-linking homo-oligomeric protein complexes of glutathione-S-transferase (GST) from Schistosoma japonicum alone or in a mixture of many other proteins. Identified cross-links were predominantly of amide origin, but six esters and thioesters were also found. The cross-linked peptides were validated against the GST monomer and dimer X-ray structures and by experimental (MS/MS) analyses. Some of the identified cross-links matched interacting peptides in the native 3D structure of GST, indicating that the structure of GST and its oligomeric complex remained primarily intact after freeze-drying. The pattern of oligomeric GST obtained in solid state was the same as that obtained in solution by Ru (II) Bpy(3)2+ catalyzed, oxidative "zero-length" cross-linking, confirming that it is feasible to use our strategy for analyzing the molecular interfaces of interacting proteins or peptides.     

Dynamics of B-DNA in the solid state

Hydrated solid B-form DNA is shown to have large amplitude motions of the phosphodiester groups and immobile bases at temperatures above 5 °C. The ³¹P nuclear magnetic resonance chemical shift powder pattern of DNA in the solid state is significantly averaged by motions that are rapid compared to 10⁴ Hz. The DNA was labelled with deuterium at the C-8 purine position by exchange. The ²H nuclear magnetic resonance spectra have complete static quadrupole powder patterns indicative of no motions fast compared to 10⁶ Hz at 50 °C.     

Conductivity and photoconductivity of NaDNA in the solid state

The d. c. conductivity of five samples of NaDNA in dry state was investigated. All specimens show similar behavior, with specific resistivity at 40°C of the order of 10¹³–10¹⁴ ohm-cm and an energy gap of E_c = 2.04–2.25 eV. Based on the Eley's model for conductivity mechanism, the possibility of conservation of an ordered structure in the dry state (temperature range 20–80°C) is discussed. This is ascribed to the interaction of electron systems of individual bases. From the activation energy values it may be estimated that 17–19 π-electrons take part in the interaction. Photoconductivity measurements indicated activation energies E_f of 0.88–0.96 eV in the visible region.