Cellulolytic enzymes of a thermotolerantAspergillus terreus strain and their action on cellulosic substrates

A thermotolerant fungal strainAspergillus terreus produced high activities of cellulolytic enzymes when grown in shake flasks for 8 days at 40°C or 14 days at 28°C in medium containing 2.5% (w/v) cellulose powder and 1% (w/v) wheat bran. There was little difference between the final activities of endo-(1,4)--glucanase (ca. 14.4 U/ml); filter paper activity (ca. 1.3 U/ml) and -glucosidase (ca. 10 U/ml). Endoglucanase had maximum activity at 60°C and pH 3.8; the other two enzymes were optimal at 60°C and pH 4.8. The maximum hydrolysis of different cellulosic substrates (about 50%) was obtained within 48 h when 1.1 U/ml of filter paper cellulase activity were employed to saccharify 100 mg alkali-treated cotton, filter paper, bagasse, and rice straw at 50°C and pH 4.8. The major end-product, glucose, was produced from all substrates, with traces of cellobiose and other larger oligosaccharides being present in rice straw hydrolysates.     

Untersuchungen zur N2-Binding bei der Verrottung von Waldgräserwurzeln unter Mikroaeroben Bedingungen

Zusammenfassung Es sollte geprüft werden, ob verrottende Wurzeln von Waldgräsern in einem mikroaeroben Milieu den N-Bindern wesentliche Mengen ausnutzbarer C-Quelle zur Verfügung stellen, so daß N-Gewinne mit dem Kjeldahlverfahren nachweisbar sind.Grobwurzeln von Calamagrostis epigaios mit C/N-Verhältnissen von 56 bis 61 wurden mit Quarzsand und Ca-Bentonit gemischt und mit einer für N-Bindung geeigneten Nährlösung überschichtet und nach Impfung bebrütet.Bei 28°C zeigten sich nach 14 Tagen erhebliche N-Gewinne, nach weiteren 7 Tagen war der N-Gehalt der Ansätze nahezu auf den Ausgangswert zurückgegangen.Der Zerkleinerungsgrad der Wurzeln hatte keinen nennenswerten Einfluß auf die Zersetzungsgeschwindigkeit. Bei 16°C und 6°C wurden fast die gleichen N-Gewinne beobachtet wie bei 28°C. Vermutlich sind die N-Verluste bei 28°C größer als bei tieferen Temperaturen.Die Untersuchungen wurden überwiegend mit Mitteln der Deutschen Forschungsgemeinschaft durchgeführt. Für diese Unterstützung sei hiermit bestens gedankt. Besonders danke ich weiterhin Herrn Prof. Laatsch für seine Anregungen und der Chemotechnikerin Frau Schmidt für die Durchführung der Analysen. Dank gebührt ferner den Herren Dr. Poschenrieder und Dr. Beck von der Bayer. Landesanstalt für Bodenkultur, Pflanzenbau und Pflanzenschutz, München, und Herrn Dr. Kutzner vom Bakteriologischen Institut der Südd. Forschungsanstalt für Milchwirtschaft in Weihenstephan b. Freising für die Einführung in mikrobiologische Arbeitsverfahren.

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Summary It was investigated if the roots of forest grasses, decomposing in a waterlogged environment, can provide substantial amounts of utilizable carbon compounds for nitrogen-fixing organisms, so that nitrogen gains can be detected by the Kjeldahl-procedure.Mixtures of quarz-sand and calcium-bentonite with coarse roots of Calamagrostis epigaios were soaked and covered with a nutrition solution suitable for N-fixation. The C/N-ratios of the roots ranged from 56 to 61. After inoculation the samples were incubated at different temperatures for various periods of time.After 14 days of incubation at 28°C considerable N-gains were obtained, but after additional 7 days the N-content of the samples almost returned to its original level.Roots ground to different particle size did not differ in their rate of decomposition. At 16°C and at 6°C almost the same N-gains were detected as at 28°C. Presumably the N-losses at 28°C are higher than at lower temperatures.

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Meinem verehrten Lehrer, Herrn Professor Laatsch, zu seinem 60. Geburtstag in Dankbarkeit gewidmet.     

Production of cellulase-free thermostable xylanases by an isolated strain of Aspergillus niger PPI, utilizing various lignocellulosic wastes

A strain of Aspergillus niger PPI having prolific xylanolytic potential was isolated and the optimum conditions for maximum xylanase production was studied, resulting in the following: 4% substrate concentration, 10% v/v inoculum size, 72 h of incubation and pH 3.5–4.5 at 28 °C. The production profile of xylanase was examined with various lignocellulosics and maximum yield was achieved with oat. The hemicellulose content of wastes was also determined and oatmeal was found to have maximum hemicellulose content followed by wheat straw, sugarcane bagasse, rice husk and gram residue respectively. The enzyme showed maximum activity at pH 4 and temperature 60 °C. However, maximum stability was achieved at pH 3.5 and temperature 55 °C. Cellulase activity was found altogether absent in the enzyme broth.     

Establishment of the white rot fungus Phanerochaete chrysosporium on unsterile straw in solid substrate fermentation systems intended for degradation of pesticides

The effects of different inoculum-loading rates and pre-treatment of wheat straw with formic acid and hot water (50 °C) on the establishment of Phanerochaete chrysosporium on unsterile straw were studied in laboratory scale and in a 1.5-m³ bioreactor. The establishment of P. chrysosporium on unsterile straw was satisfactory. Phanerochaete chrysosporium and other fungi, which developed simultaneously, were able to produce the activity necessary to degrade two herbicides, bentazon and MCPA (4-chloro-2-methylphenoxyacetic acid) in 20 days (65 and 75%, respectively). The decrease of both herbicides coincided with the presence of the activity of the lignin-degrading enzymes lignin peroxidase and manganese peroxidase/laccase. Extensive growth of P. chrysosporium or other lignin-degrading fungi on unsterile straw would be excellent for inexpensive solid substrate systems intended for degradation of pesticides.     

Utilization of new naturally occurring strains and supplementation to improve the biological efficiency of the edible mushroom <Emphasis Type="Italic">Agrocybe cylindracea</Emphasis>

To evaluate the importance of searching new naturally occurring strains to raise yields in mushroom production, eight wild and four commercial strains of Agrocybe cylindracea were cultivated on wheat straw. The highest biological efficiencies (BE) (54.5-72.4%) were obtained with three wild and two commercial strains when cultured on non-supplemented wheat straw. Rolled oats or soybean flour supplementation were tested using three selected strains, increasing BEs up to 1.2, 0.5 and 0.7-fold, respectively. This effect of supplementation was stronger in the Asiatic wild strain, yielding up to 41.1 and 30% more than the two other strains with rolled oats and soybean flour, respectively. The Asiatic wild strain cultivated with soybean flour supplementation achieved an average biological efficiency of 179%, to our knowledge, the highest reported for this species. These results show the importance of searching for new naturally occurring strains in combination with supplemented wheat straw substrate for raising yields in A. cylindracea cultivation.     

The temperature coefficient of the duration of life in Tubularia Crocea

Zusammenfassung Der Temperaturkoeffizient für die Lebensdauer vonTubularia crocea wurde für das Temperaturintervall 36°–25° C. bestimmt. Es wurde gefunden, daß derselbe etwa 2 für einen Temperaturunterschied von 1° beträgt. Das ist derselbe Temperaturkoeffizient, denLoeb für die Lebensdauer der Seeigeleier für das Temperaturintervall 32°–20° C. gefunden hat.

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I wish to thank ProfessorLoeb for his many helpful suggestions and criticisms.     

Development, survival and reproduction of Euseius finlandicus (Acari: Phytoseiidae) at different constant temperatures

Development, survival and reproduction of Euseius finlandicus Oudemans were studied at seven constant temperatures (15, 20, 25, 27, 30, 32 and 34°C) in the laboratory. Within the temperature range tested, developmental period from egg to adult varied from 148 to 360.5h and 133.7 to 336.5h for females and males, respectively. The lower thermal threshold for immature development for females and males was 8.9 and 6.4°C, respectively. Survival during immature development exceeded 90% at all the temperatures from 15 to 32°C, but at 34°C an abrupt decline was recorded. Female longevity decreased gradually from 82.7d at 15°C to 12.2 d at 34°C. The mean generation time ranged from 44.3d at 15°C to 15.9d at 32°C. The highest r _m value (0.2817) was obtained at 30°C and the lowest at 15°C (0.0976). Temperatures above 30°C had an adverse effect on population increase.     

The growth of Epidermophyton floccosum and E. stockdaleae at different temperatures

The ability of 17 strains of genus Epidermophyton (15 strains belonging to Epidermophyton floccosum, one to E. floccosum var. nigricans and one to E. stockdaleae) to grow at different temperatures (4 °C, 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C) was stated.The strains were inoculated on Sabouraud Dextrose Agar and regularly controled over a period of 14 days when the plates were incubated at 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C, and over a period of 70 days when the temperature was 4 °C. The optimal growth of E. floccosum was observed at 28 °C and 31 °C, and no signs of growth were recorded neither at 4 °C nor at 40 °C. The optimal development of E. stockdaleae was observed at 25 °C and 28 °C. This species grew from 4 °C to 31 °C.     

Low temperature thresholds for flight in Aphis fabae Scop.

The temperature thresholds for wing-beating and successful flight in alienicolae of Aphis fabae were found by flying tethered aphids in a falling temperature and by dropping free aphids in still air at different temperatures. The median temperature thresholds for wing-beating, horizontal and upward flight were 6.5°, 13° and 15° C respectively.

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Zusammenfassung Die Temperaturschwellen für Flügelschlag und erfolgreichen Flug wurden bei alienicolen Aphis fabae Scop. an gefesselten Aphiden bei fallenden Temperaturen ermittelt sowie durch Fallenlassen freier Blattläuse in ruhige Luft bei verschiedenen Temperaturen.Die mittlere Temperaturschwelle für Flügelschlag betrug 6,5° C (Flügelschläge eine Minute andauernd) und wurde vom Feuchtigkeitsgehalt der Luft sowie von der Abkühlungsrate (sowie möglicherweise von der Flugdauer) beeinflußt. Unter 9–10° C hielt der Flügelschlag nur für eine kurze Zeit an und die Schlagamplitude war bei diesen Temperaturen im allgemeinen gering.Die mittlere Temperaturschwelle für horizontalen Flug lag bei 13° C (unter 10° vollständige Verhinderung) und für Aufwärtsflug bei 15° C (unter 12° völlige Hemmung); die höhere Schwelle für den Aufwärtsflug steht wahrscheinlich mit höherem Stoffwechselbedarf in Verbindung. Nach einem Aufenthalt von 24 Stunden bei niederen Temperaturen (5–15° C) vor dem Flug flogen bei 12–13° C weniger Blattläuse, als wenn sie bei 20° C gehalten worden waren. Diese Ergebnisse gelten nur für die ersten wenigen Sekunden des Fluges.

     

Enzymatic hydrolysis of rice straw and corn stalks for monosugars production

Rice straw and corn stalks were used as fermentation substrate for the evaluation of cellulases activity secreted by different organisms. The substrates were pretreated with alkaline hydrogen peroxide (AHP) for 6 h at 30 and 60 °C. From the fermentation studies, rice straw and corn stalks substrates showed the highest cellulases activity after 96 h at 60 °C of pre-treatment.     

The dispersion of Trogoderma granarium in a temperature gradient and comparison with other stored product beetles

The response of stored-product beetles to a temperature gradient was measured with particular emphasis on the initial distribution. When initially introduced at the centre, the following zones were preferred: for Trogoderma granarium 28–33°C (The peak response of females shifts toward the warm side if they are mixed with males, in comparison to the response of female population). Tribolium castaneum 25–34°, Oryzaephilus surinamensis 22–26°, Tenebrio molitor 23–28°, Sitophilus oryzae 20–24°, Callosobruchus maculatus 22–24°, Rhyzopertha dominica 22–28°. T. castaneum and T. molitor aggregated at the corners under isothermal conditions. Some of the species, especially C. maculatus, show hardly any dispersal either in a temperature gradient or under isothermal conditions.

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Zusammenfassung Die Reaktion von vorratsschädlichen Käfern gegenüber einem Temperaturgradienten wurde mit besonderer Berücksichtigung der Ausgangsverteilung gemessen. Bei ursprünglicher Einbringung in das Zentrum wurden folgende Vorzugsbereiche festgestellt; für Trogoderma granarium 28–33°. Der Reaktionsgipfel der Weibchen verschiebt nach der warmen Seite wenn sie mit Männchen gemischt sind, in Vergleichung zu der Responz der weiblichen Population, für Tribolium castaneum 25–34°, für Oryzaephilus surinamensis 22–26°, für Tenebrio molitor 23–28°, für Sitophilus oryzae 20–24°, für Callosobruchus maculatus 22–24° und für Rhyzopertha dominica 22–28°. T. castaneum und T. molitor sammelten sich unter isothermalen Bedingungen in den Ecken. Einige der Arten zeigten weder in einem Temperaturgefälle noch unter isothermalen Bedingungen irgendeine geordnete Verteilung.

     

Production of extracellular enzymes during the solubilisation of straw by Thermomonospora fusca BD25

The production of three extracellular enzymes during the solubilisation of ball-milled wheat straw by seven actinomycete strains, was examined. A general correlation was observed between the production of extracellular enzymes (xylanases, endoglucanases and peroxidases) and the formation of the solubilised lignocellulose intermediate product (APPL), with the thermophilic actinomycete Thermomonospora fusca BD25 exhibiting greatest extracellular enzyme activity and highest APPL production. Production of all three enzymes; endoxylanase, endoglucanase and peroxidase, and lignocellulose solubilisation, occured during primary growth with maximum activity at the end of the exponential phase (48–96 h). The inducibility and stability of extracellular enzymes from T. fusca were further characterised. When xylan replaced ball-milled wheat straw as the growth substrate, reduced enzyme activities were observed (28–96% reduction in enzyme activities), whereas carboxymethylcellulose was found to be a poor inducer of all three enzyme activities (80–100% reduction in enzyme activities). The pH and temperature optima for extracellular enzyme activities from T. fusca was found to be pH 7.0–8.0 and 60°C, respectively. Analysis of concentrated crude supernatant from T. fusca by native polyacrylamide gel electrophoresis revealed the existence of two non-haem peroxidases. The stability of the extracellular lignocellulose-degrading enzymes for T. fusca suggest their suitability for future biotechnological processes such as biobleaching.     

Energieumsatz in Abh?ngigkeit von der Umgebungstemperatur beim KolibriOcreatus u. underwoodii

Zusammenfassung Bei der südamerikanischen KolibriartOcreatus u. underwoodii (2.7 g±0.09 SD, n=3) wurde der Ruhe- und Flugstoffwechsel in Abhängigkeit von der Umgebungstemperatur (3° bis 34° C) bei Licht und ohne Nahrungsentzug untersucht, sowie der stündliche Energieverbrauch ermittelt.1. Der Ruhestoffwechsel stieg linear bei fallender Umgebungstemperatur (r=0.95±0.04 SD, n=3).2. Der Flugstoffwechsel zeigte eine dem Ruhestoffwechsel entsprechende Abhängigkeit von der Umgebungstemperatur.3. FürOcreatus u. underwoodii wurden für Sitzen bzw. Fliegen mit 199.2 mW/g bzw. 325.3 mW/g die höchsten für homöotherme Tiere bisher ermittelten Wärmeproduktionsraten gemessen.4. Im getesteten Umgebungstemperaturbereich schwankte die Körpertemperatur bei den drei Individuen zwischen 38.8° und 39.9° C.5. Der für 25° C Umgebungstemperatur berechnete Energieverbrauch betrug ca. 1030 J/h.6. Zur Deckung des Energiebedarfs mußOcreatus u. underwoodii stündlich z. B. 205Salvia-Blüten besuchen.

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Energetical responses to various ambient temperatures in the hummingbirdOcreatus u. underwoodii

Summary Metabolism of resting and flyingOcreatus u. underwoodii (2.7 g±0.09 SD, n=3) was measured at varying ambient temperatures (3°–34° C). All experiments were conducted in light. In the metabolic chamber the bird had access to food. The caloric expenses were calculated for one hour.1. Metabolism of restingOcreatus u. underwoodii increased linearly with falling ambient temperature (r=0.95±0.04 SD, n=3).2. During flight O₂-consumption showed the same relation to ambient temperature as in resting birds.3 With 199.2 mW/g for resting and 325.3 mW/g for flight the highest rates for heat production in homeothermic animals were registrated.4. In the tested range of ambient temperature body temperature varied in all 3 individuals from 38.8° to 39.9° C.5. The caloric expenses at 25° C ambient temperature, the most commonly experienced temperature in the natural environment of this hummingbird species, were about 1030 J/h.6. To gain its energy requirementsOcreatus u. underwoodii has to visit e. g. about 205 Salvia flowers per hour.

     

The role of the diffusion of oxygen in the respiration of rat diaphragm at different temperatures

Summary 1. Data are presented to support the hypothesis that the respiration rate of hemidiaphragms and tissue slices is restrictedin vitro because oxygen fails to reach the innermost layers of the tissue.2. Calculation of limiting thickness fromWarburg's formula (Equation 1) requires use of a value for QO₂, but the true value is unknown since it is in turn dependent upon thickness. The dilemma is not avoided by making thinner slices because this damages tissues and reduces the QO₂.3. We found that for rat diaphragm a plot of log QO₂ versus 1/T yields a straight line between -6° and 13.5° C, and a line of half that slope from 18° to 38° C.4. Equations are presented for calculating QO₂ at these temperatures, assuming that oxygenation is incomplete above about 18° C. The calculated values agree well with the observed values. Further, QO₂ of diaphragm at 33° C was higher at an oxygen pressure of 2 atmospheres than 1 atmosphere in agreement with theoretical considerations.

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Die Bedeutung der Sauerstoffdiffusion für die Atmung des Rattendiaphragmas bei verschiedenen Temperaturen

Kurzfassung Es werden Ergebnisse vorgelegt, welche die Hypothese untermauern, daß die Respirationsrate von Hemidiaphragmen und Gewebescheiben in vitro eingeschränkt ist, weil der Sauerstoff die innersten Gewebeschichten nicht zu erreichen vermag. Die Errechnung der kritischen Gewebedicke nachWarburgs Formel erfordert die Einsetzung des Wertes für QO₂, der ist aber unbekannt, da er ja selbst wiederum von der Dicke abhängt. Man kann diesem Dilemma nicht dadurch ausweichen, daß man dünnere Scheiben verwendet; denn das würde die Gewebe beschädigen und so den QO₂ herabsetzen. Wir haben festgestellt, daß die Auftragung von log QO₂ gegen 1/T für das Rattendiaphragma eine gerade Linie ergibt zwischen -6° und 13,5° C und eine Linie mit dem halben Anstiegswinkel zwischen 18° und 38° C. Unter der Annahme, daß das Sauerstoffangebot über etwa 18° C unzureichend wird, werden Gleichungen gegeben für die Errechnung des QO₂ bei den oben genannten Temperaturen. Die errechneten Daten stimmen mit den beobachteten Werten gut überein. Bei 33° C war der QO₂-Wert höher bei einem Sauerstoffdruck von 2 Atmosphären als bei einem solchen von 1 Atmosphäre; dieser Sachverhalt steht in Übereinstimmung mit den theoretischen Erörterungen.

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This work was supported in part by a grant from the National Science Foundation.     

Puparial duration in Glossina morsitans orientalis under conditions of constant temperature

Puparial durations and rates of development at constant temperatures have been estimated for puparia derived from colony and field populations. Rates of development may now be predicted over the temperature range 8° to 32° C, estimates for temperature less than 16° having been obtained by a technique using alternating temperature regimes. No evidence was found for localised racial variation, but some evidence is presented for a larval conditioning effect.

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Zusammenfassung Dauer des Puparium-Stadiums und der Entwicklungsraten bei konstanten Temperaturen wurden für Puparien ermittelt, die aus Zucht-und Freilandpopulationen stammten. Die Entwicklungsraten können nun über einen Temperaturbereich von 8 bis 32° vorausgesagt werden, wobei die Werte für Temperaturen unter 16° durch eine Methode mit Wechseltemperaturen gewonnen wurden. Es konnten keine Anhaltspunkte für lokale Rassenunterschiede festgestellt werden, doch ergab sich die Wahrscheinlichkeit für einen Einfluß der Temperaturen, die zuvor auf die Larven eingewirkt haben.

     

Effects of species of VA-mycorrhizal fungi on growth and mineral uptake of sorghum at different temperatures

Sorghum [Sorghum bicolor (L.) Moench] plants were grown in growth chambers at 20, 25 and 30°C in a low P Typic Argiudoll (3.65 µg P g^–1 soil, pH 8.3) inoculated with Glomus fasciculatum, Glomus intraradices, and Glomus macrocarpum to determine effects of vesicular-arbuscular mycorrhizal fungi (VAMF) species on plant growth and mineral nutrient uptake. Sorghum root colonization by VAMF and plant responses to Glomus species were temperature dependent. G. macrocarpum colonized sorghum roots best and enhanced plant growth and mineral uptake considerably more than the other VAMF species, especially at 30°C. G. fasciculatum enhanced shoot growth at 20 and 25°C, and mineral uptake only at 20°C. G. intraradices depressed shoot growth and mineral uptake at 30°C. G. macrocarpum enhanced shoot P, K, and Zn at all temperatures, and Fe at 25 and 30°C above that which could be accounted for by increased biomass. Sorghum plant growth responses to colonization by VAMF species may need to be evaluated at different temperatures to optimize beneficial effects.     

The pick-up of C14-DDT at different temperatures

Mosquito larvae, Aedes aegypti, picked up progressively greater amounts of C¹⁴ labeled DDT with ascending temperatures. The pick-up relationship contrasted with per cent mortality which showed a negative temperature coefficient. The exposure temperatures were 10°, 20° and 30° C. A similar relationship of pick-up of DDT occurred when heads, thoraces, or abdomens of the larvae were compared separately. The thorax contained greater concentrations than heads or abdomens at 30° and 20° C. At 10° C the heads contain more than thoraces and abdomens, but the amount was still less than that picked up at 20° and 30° C.The results show a positive coefficient of pick-up of DDT but a negative temperature coefficient for per cent mortality provided the concentration of DDT is not too high. The latter relationship agrees with considerable earlier research. The explanation for the negative temperature effect of DDT is still not understood, but we have evidence that the effect is not positively related to pick-up by whole larvae or portions of whole larvae.

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Zusammenfassung Mückenlarven (Aedes aegypti) nahmen um so größere Mengen von ¹⁴C-markiertem DDT auf, je mehr die Temperatur anstieg. Im Gegensatz dazu zeigte die prozentuale Mortalität einen negativen Temperaturkoeffiziente. Die Untersuchungstemperaturen betrugen 10, 20 und 30°. Eine ähnliche DDT-Aufnahme-Beziehung ergab sich, wenn Köpfe, Brustabschnitte oder Abdomina der Larven getrennt verglichen wurden. Bei 30 und 20° wiesen die Brustabschnitte größere Konzentrationen auf als die Köpfe und Abdomina. Bei 10° enthielten die Köpfe mehr als die Abdomina und Brustabschnitte, aber die aufgenommene Menge war doch geringer als bei 20 und 30°.Die Ergebnisse zeigen einen positiven Temperaturkoeffizienten für die DDT-Aufnahme, aber einen negativen für die prozentuale Mortalität unter der Voraussetzung, daß die DDT-konzentration nicht zu hoch ist. Die zweite Beziehung stimmt mit beträchtlich früheren Untersuchungen überein. Eine Erklärung für diesen negativen Temperatureffekt des DDT ist noch nicht gefunden, aber es scheint, daß diese Wirkung keine positive Korrelation zur DDT-Aufnahme ganzer Larven oder bei Teilen ganzer Larven aufweist.

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Paper No. 5188 Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul 1, Minnesota.     

Thermoleophilum album gen. nov. and sp. nov., a bacterium obligate for thermophily and n-alkane substrates

Several bacterial strains that are obligate for both thermophily and hydrocarbon utilization have been isolated from a number of thermal and non-thermal environments. Mud and water samples obtained from geographic sites across the United States were subjected to enrichment procedures at 60° C with n-heptadecane as sole growth substrate. Organisms forming very small white colonies on agar surfaces were often evident on primary enrichment. These bacteria were Gram negative, aerobic, small, and rodshaped. They lacked pigmentation, motility, and the ability to form endospores. Growth occurred in the temperature range from 45° C to 70° C with the optimum around 60° C and at a pH near neutrality. Only n-alkanes from 13 to 20 carbons in length were utilized by these organisms as growth substrate. The mol% guanine plus cytosine values for these strains were between 68 and 70%. The physiological and morphological characteristics of these organisms are distinctly different from any previously described thermophilic microbes. It is proposed that they be placed in a new genus, Thermoleophilum gen. nov. with the type species being Thermoleophilum album gen. nov., sp. nov. The type strain in ATCC 35263.Paper number 8953 of the Journal Series of the North Carolina Agricultural Research Service Raleigh, NC 27695, USA     

Production and characterization of xylanases of a Bacillus strain isolated from soil

Xylanase production was performed by growing a Bacillus isolate on agricultural by-products, wheat straw, wheat bran, corn cobs and cotton bagasse. A maximum xylanase activity of 180 U/ml was obtained together with a cellulase activity of 0.03 U/ml on 4 (w/v) corn cobs. Electrophoretic analysis showed the presence of three endo--1, 4-xylanases having molecular weights of about 22, 23 and 40 kDa. Xylanolytic activity was stable up to 50 °C in the pH range of 4.5–10 and the highest activity was observed at 70 °C and pH 6.5.     

Enhanced production and characterization of a highly thermostable alkaline protease from Bacillus sp. P-2

An obligatory alkalophilic Bacillus sp. P-2, which produced a thermostable alkaline protease was isolated by selective screening from water samples. Protease production at 30 °C in static conditions was highest (66 U/ml) when glucose (1% w/v) was used with combination of yeast extract and peptone (0.25% w/v, each), in the basal medium. Protease production by Bacillus sp. P-2 was suppressed up to 90% when inorganic nitrogen sources were supplemented in the production medium. Among the various agro-byproducts used in different growth systems (solid state, submerged fermentation and biphasic system), wheat bran was found to be the best in terms of maximum enhancement of protease yield as compared to rice bran and sunflower seed cake. The protease was optimally active at pH 9.6, retaining more than 80% of its activity in the pH range of 7–10. The optimum temperature for maximum protease activity was 90 °C. The enzyme was stable at 90 °C for more than 1h and retained 95 and 37% of its activity at 99 °C and 121 °C, respectively, after 1 h. The half-life of protease at 121 °C was 47 min.