Sulfite action on ribulosediphosphate carboxylase in the lichen Pseudevernia furfuracea

Summary Ribulosediphosphate carboxylase can be extracted from Pseudevernia furfuracea, either by Triton X-100 or by pretreatment with liquid nitrogen. With respect to HCO₃^– the K_mis 33 mM. The enzyme is competitively inhibited by sulfite, as is the case with spinach chloroplasts. The K_ivalue (15.5–18.5 mM sulfite) indicates that in lichens the enzyme is not more sensitive than that in spinach. Thus the extreme sensitivity of lichens to SO₂ is not based on low tolerance at the enzymatic level, but is due to a low degree of avoidance.     

The use of immobilized cells to stabilize orsellinate depside hydrolase of Pseudevernia furfuracea

Mixed cells of Pseudevennia Lun-Lunacea thallus have been entrapped in polyacrylamide gel and used in a continuous column process to hydrolyze evernic acid. Equimolar amounts of both orsellinic and everninic acids are recovered. The activity of entrapped cells, which contain orsellinate depside hydrolase, is unaltered over a period of two months.     

Evaluation of genotoxicity of Pseudevernia furfuracea (L.) Zopf by RAPD analysis

We investigated the suitability and applicability of Pseudevernia furfuracea (L.) Zopf for environmental genotoxicity assessment. P. furfuracea lichen specimens were collected from 10 different Pinus species, in every 5 km, starting from around an iron-steel factory located in the central area of Karabük Province up to Yenice Forest. The impact of the pollution sources such as iron-steel factory, roads and railroads, industry, heavy traffic, and waste treatment plants on the heavy metal accumulation in lichens is known. DNA changes in P. furfuracea samples exposed naturally to various polluted sites were analyzed by RAPD to know the influence of the environmental pollution on the hereditary material of the organisms. Twenty-five different primers were tested and 10 yielded clear and reproducible bands. The present study shows the suitability of the lichen samples for the detection of genotoxicity and also provides information about the level of potential genotoxic agents around a steel mill.     

Antimicrobial activity of extracts of chemical races of the lichen Pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents

The antimicrobial activity and the MIC values of the ethanol, chloroform, diethyl ether, and acetone extracts of the chemical races of Pseudevernia furfuracea (var. furfuracea and var. ceratea) and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents have been investigated against some microorganisms. Nearly all extracts of both chemical races showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, Candida albicans, Candida glabrata, Alternaria alternata, Ascochyta rabiei, Aspergillus niger, Fusarium culmorum, Fusarium moniliforme, Fusarium oxysporum, Fusarium solani, and Penicillium notatum. There was no antimicrobial activity of the extracts against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Pseudomonas syringae, Salmonella typhimurium, Alternaria citri, Alternaria tenuissima, and Gaeumannomyces graminis. Chloroatranorin and olivetoric acid were active against the same microorganisms with few exceptions. Physodic acid was active against about the same bacteria and yeasts and inactive against all of the filamentous fungi tested. Also no activity of atranorin against the filamentous fungi was observed.     

Production of quorum-sensing-related signal molecules by epiphytic bacteria inhabiting wheat heads

The production of quorum-sensing-related signal molecules (QSRMs) among culturable bacteria comprising the community on wheat heads was investigated. The taxonomic position of 186 bacterial isolates obtained from ten heads was inferred based on 16S rRNA gene sequences, and their QSRM production was determined using two bioreporter strains of N-acylhomoserine lactones. Approximately 33% of isolates produced QSRMs, though the proportion of QSRM-producing isolates on a wheat head was significantly negatively correlated with population size. Most of the producing isolates were Pantoea species, most commonly Pantoea ananatis. Furthermore, the proportion of Pantoea ananatis that produced QSRMs was significantly negatively correlated with the number of bacterial genera (community richness) on each head. Finally, community richness was positively correlated with population size. Qualitative analysis using thin-layer-chromatography revealed that the QSRMs of Pantoea isolates were composed of at least two compounds. This is the first report indicating that Pantoea ananatis isolates inhabiting wheat heads are capable of producing QSRMs. QSRM production by Pantoea spp. may contribute to the predominance of this genus on wheat heads, particularly at relatively low population densities and community diversity.     

The occurrence of lichen phenolics in the photobiont cells of Evernia prunastri

Photobiont cells of Evernia prunastri were isolated by filtration through a bed of Sepharose 2B. Algal preparations did not contain fungal contamination, as revealed by the absence of mannitol. Isolated photobionts contain the four Evernia phenolics, although repeated superficial washes with polyvinylpyrrolidone remove from these cells 81% atranorin, 51% chloroatranorin, 94% evernic acid and 82% usnic acid.     

Production of epoxides from gaseous alkenes by resting-cell suspensions and immobilized cells of alkene-utilizing bacteria

Summary Newly isolated and already available strains of alkene-utilizing bacteria were able to oxidize ethene, propene or 1-butene to the respective 1,2-epoxides. Resting-cell suspensions of organisms isolated on propene and butene, when grown on these substrates converted ethene quantitatively to epoxyethane. Some, but not all ethene-utilizing strains accumulated 1,2-epoxypropane or 1,2-epoxybutane when propene or butene was supplied, although not quantitatively because the epoxides produced were partially further metabolized. Suitable epoxide producers which eventually may be employed as biocatalysts in a biotechnological process were used for immobilization in calcium alginate and K-carrageenan; after immobilization, 60%–100% activity for epoxide production was retained.     

Production of cellulase by immobilized whole cells of Haloarcula

Halophilic Archaea are adapted to a life in the extreme conditions and some of them are capable of growth on cellulosic waste as carbon and energy source by producing cellulase enzyme. The production of cellulase using free and immobilized cells of halophilic archaeal strain Haloarcula 2TK2 isolated from Tuzkoy Salt Mine and capable of producing cellulose was studied. The cells were cultured in a liquid medium containing 2.5 M NaCl to obtain the maximum cellulase activity and immobilized on agarose or polyacrylamide or alginate. Optimal salt dependence of free and immobilized cells of Haloarcula 2TK2 was established and the effects of pH and temperature were investigated. Immobilization to Na-alginate enhanced the enzymatic activity of the Haloarchaeal cells when compared to free cells and other polymeric supports. From the results obtained it is reasonable to infer that decomposition of plant polymers into simpler end products does occur at high salinities and cellulase producing haloarchael cells may be potentially utilized for the treatment of hypersaline waste water to remove cellulose.     

Production of solavetivone by immobilized cells of Hyoscyamus muticus

Summary The secretion of solavetivone, a phytoalexin, by the cells of Hyoscyamus muticus in response to fungal elicitation has been enhanced by gel entrapment in calcium alginate. The immobilized cells produced 53% higher product and exhibited sustained biosynthetic activity in repeated batch cycles when compared with suspended cells. Providing a non-elicited media exchange and a sufficient interval of time between repeated infection (elicitation) gave greater productivity. Apparently the cells need a period to recover from the infection.     

Production of mead by immobilized cells of Hansenula anomala

Summary Mead was produced by immobilized cells of Hansenula anomala in calcium alginate gels. The immobilized cell beads of 3 mm diameter packed in column reactors of dimensions 2.2x60, 4x40 and 8x80 cm, produced mead containing maximum concentrations of ethanol and ethyl acetate of 70 g/l and 730 mg/l, respectively at a dilution rate of 0.1 h^–1. The maximum alcohol productivity achieved was 23.1 g/l·h at a dilution rate of 0.33 h^–1. With intermittent regenerations of the cells the reactor operated continuously for 110 days. This process enables the quick production of matured mead by a single culture and the elimination of the traditionally used long aging periods.     

Fermentation of fructans by epiphytic lactic acid bacteria

A total of 712 strains of lactic acid bacteria isolated from forage grasses were studied for their ability to ferment fructans of phlein- as well as inulin-type. Only 16 strains utilized phlein and eight of these also fermented inulin. They were identified as Lactobacillus paracasei subsp. paracasei, Lact. plantarum, Lact. brevis and Pediococcus pentosaceus . In the species Lact. paracasei subsp. paracasei , all strains gave positive results, whereas the other positive strains possessed unique properties within their own species. In all but two cases (strains of the species Lact. plantarum ), the phlein was more intensively fermented than the inulin, as indicated by a lower pH and a higher lactic acid concentration. On the basis of the outcome of this study it seems worthwhile to inoculate grasses of low sugar content before ensiling with an active strain that can ferment fructans.     

Production of daunorubicin by immobilized growing Streptomyces peucetius cells

Summary Streptomyces peucetius cells were immobilized by entrapment in calcium alginate and a photosensitive synthetic polymer, and used for the production of daunorubicin (daunomycin), which is known to be an antitumour reagent. The use of cultivation media removed insoluble components in a natural medium prevented rapid decrease in daunorubicin titer after maximum production. These entrapped cells could be used at least five times for repeated daunorubicin production; the total cultivation period was 45 days.     

Production of D-phenylglycine-related amino acids by immobilized microbial cells

Bacterial dihydropyrimidinase was shown to catalyze the hydrolytic cleavage of various 5-substituted hydantoins to the corresponding N-carbamyl-D-amino acids under alkaline conditions. Therefore, an enzymatic method for preparing the D-forms of phenylglycine-related amino acids was developed using immobilized bacterial cells with high enzyme activity. Alkalophilic bacteria were a good enzyme source for this process. The process is simple and economical for use in the production of various amino acids with the D-configuration.     

Production of tylosin and nikkomycin by immobilized Streptomyces cells

Summary Mycelia of Streptomyces sp. T 59-235 and Streptomyces tendae Tü 901 (producing the antibiotics tylosin and nikkomycin, resp.) were immobilized in different carriers. With both organisms best antibiotic production was observed in calcium alginate gel.Influence of aeration, cell density and flow rate on antibiotic production was investigated in batch fermentation and in a continuous system (air-bubbled reactor).In batch fermentation, immobilization prolongued the production phase from 72 to 120 h (Streptomyces T 59-235) and from 72 to 96 h (S. tendae). The relative productivity of immobilized cells was 40 to 50% compared to that of free mycelia in both cases.In continuous tylosin fermentation highest production rate was observed in a medium nearly saturated with oxygen.Nikkomycin production by immobilized S. tendae could be maintained for longer than 350 h in a continuous system. The production rate depended on cell density and flow rate of the medium. The maximum specific productivity was 100% compared to that of free mycelium in batch culture.     

Production of lysine by using immobilized livingCorynebacterium sp cells

Summary Lysine production by immobilizedCorynebacterium sp cells in alginate gel beads was investigated in flasks. ImmobilizedCorynebacterium sp cells exhibited a slightly greater lysine production than free cells and accumulated 60 g/l of L-lysine at maximum, when cultured for 120h in a medium containing 200g/l glucose as carbon source. Several factors, such as inoculum size, incubation time and alginate gel concentration were examined in order to improve lysine production by immobilized growing cells.     

Production of NADP by immobilized cells with NAD kinase

By the radiation-copolymerization method with polyethylene glycoldimethacrylate (PGD) as a main polymerizable reagent, microbial cells of Brevibacterium ammoniagenes were immobilized with high specific activity of NAD kinase and high mechanical strength. The reagents used for the immobilization such as PGD, polyvinyl alcohol (PVA), and N,N'-methylenebisacrylamide (Bis) did not inversely affect the enzyme activity. Freezing and irradiation treatment of the cell-reagent solution did not inactivate the enzyme either, but longer freezing time or a lower irradiation dose (less than 400 krad) resulted in the unsatisfactory mechanical strength of the immobilized cells. Almost all of NAD and ATP consumed were converted into NADP within three hours reaction time. The drum reactor was found to be ideal for the reaction of immobilized cells, since it gave little mechanical stress to the immobilized cells for the effective mixing of the cells and the substrates. The immobilized cells were subjected to three hours reaction repeatedly for 30 times without any activity loss.     

Production of cephalosporin C by immobilized cells of Cephalosporium acremonium

Cephalosporium acremonium ATCC 48272 cells were immobilized on various adsorbents and in various entrapment matrices. The influence of the incubation period, the best immobilization technique and the optimum concentrations of the selected matrices were investigated. From the results of the repeated batch fermentation in shake flasks, a good level of antibiotic was maintained for a period of about 19 days using 4% calcium alginate and 1% glass wool as entrapment and adsorbent supports, respectively.     

Production of mead by immobilized whole cells of Saccharomyces cerevisiae

Summary The continuous production of mead was achieved with whole cells of Saccharomyces cerevisiae immobilized in calcium alginate gels. The alcohol production was stable in the pH range of 2.5–6.0 and a temperature range of 18–30°C with a sharp increase at 35°C. The process reduced the problems of contamination and secondary fermentation which are associated with traditional mead production.     

Production of L-tartaric acid by immobilized bacterial cells Nocardia tartaricans

Nocardia tartaricans converted sodium cis-epoxysuccinate to L-tartrate. The highest cis-epoxysuccinate hydrolase activity (37.7 U mg^–1) was obtained with 0.02% (w/v) sodium deoxycholate, but this inactivated the cells. Immobilized N. tartaricans in pectate gel showed higher enzyme activity (51 U mg ^–1) compare to the free cells (8.9 U mg ^–1). After 450 days, the immobilized cells still possessed 0.65 U mg ^–1, i.e. 30% of the initial enzyme activity.