Nathan Zuntz and 100 Years Non-Protein-Nitrogen Research in Berlin

The advantages and disadvantages of metabolisable and net energy as parameters of energetic feed evaluation are discussed. For a global comprehensive standardisation of the energetic feed evaluation, the metabolisable energy (ME) will have a preference. The principles of an energetic feed evaluation system with ME as parameter are explained according to which the subsystems for all species of animals should be worked out uniformly. The subsystems for the most important farm animals integrate themselves in addition to ME for predicting the energy and food needs of the animal also the net energy (NE) by taking a standard feedstuff to characterise the relative energetic feed value of the feedstuffs for one or more partial performances of the animal species concerned.     

The growth rate-limiting reaction in methanol-assimilating yeasts

Abstract The maximum growth rate of methylotrophic yeasts during growth on methanol is about 0.2 h⁻¹. Since they are able to grow faster on substrates such as glucose we tried to identify the putative limiting step in methanol metabolism within the assimilatory pathway, leading to the formation of a major precursor for biosyntheses, or within the linear dissimilatory sequence. Growth experiments with mixed substrates and determination of some kinetic parameters allowed us to restrict the number of possible pacemaker enzymes. The dissimilatory sequence does not seem to be growth-rate limiting. This also applies to transketolase, transaldolase and fructose-1,6-bisphosphatase. Surprisingly, methanol oxidase appears to be the prime candidate.     

Vergleich der Kot- und Harn-N-Trennung in 2 verschiedenen Ratten-Stoffwechselkäfigsystemen

The energy availability from the feedstuffs and the energy requirement of animals are characterized by the metabolizable energy. The metabolizable energy of the feed (feedstuff, ration) is interpreted as potential energy.

For comparative analyses within and between animal species with regard to the energetic feed value of single feedstuffs the parameter “relative fat retention effect” is introduced.

The metabolizable energy of a ration is estimated in consideration of live weight and protein production (protein in body gain and egg). The energy requirement is calculated factorial ‐ as a rule by the partial utilization of metabolizable energy for partial performances (k_f, k _p, k _o) in connection with the level and kind of partial performance; k _m is not used in the system.

The proposed system of energetic feed evaluation is available as “computer variant” as well as “manual variant”. The computer programme is fitted first of all to application in research and teaching. (The complete documentation of the proposal for energetic feed evaluation for fowls including a diskette for using of the computer programme for scientific application can be claimed in limited extend from the author.)     

Intensive Markstammkohlfütterung und ihr Einfluß auf Verdaulichkeit,Blutbild sowie Blut-, Milch- und Harnbestandteile von Kühen,Ochsen und Schafen

Abstract

The effect of energy deposition and the utilization of feedstuffs and rations were compared between growing and adult pigs. The good agreement in the data leads to the conclusion, that the energy deposition effect of feedstuffs and rations in growing pigs can be estimated with an equation based on measurements in adult pigs. Exceptions are feedstuffs which are digested bacterially to a relatively high part in the large intestine, as e. g. sugar beet pulp, raw potatoes or similar feed.

Es wurden Vergleiche zur Energieansatzwirkung und Energieverwertung von Futtermitteln und Rationen zwischen wachsenden und adulten Schweinen durchgeführt. Die gute Übereinstimmung in den Ergebnissen führt zu der Schlußfolgerung, daß die Energieansatzwirkung von Futtermitteln und Rationen beim wachsenden Schwein mit einer Gleichung geschätzt werden kann, die auf Messungen am ausgewachsenen Schwein basiert. Ausnahmen sind Futtermittel, die zu einem größeren Anteil bakteriell im Dickdarm verdaut werden, wie z.B. Trockenschnitzel, rohe Kartoffeln oder ähnliche Futtermittel.     

The energetic feed evaluation in Germany

The paper describes the energetic feed evaluation systems for ruminants, pigs, poultry and horses presently used in Germany. During the last ten years the “Ausschuß für Bedarfsnormen”; (AfB; Committee of Nutrient Requirements) of the “Gesellschaft für Ernährungsphysiologie”; (GfE, Society of Nutritional Physiology) introduced new recommendations for energy requirements of domestic animals including national and international references.

The energetic requirements were factorially deduced (demand for maintenance and various performances) under consideration of partial efficiency of utilized metabolizable energy (ME) for various performances (k‐values). Except for lactating cows (Net Energy Lactation; NEL) the energy requirements of other ruminants as well as of pigs and poultry are given in ME. At present, the energy requirement of horses is still expressed as digestible energy (DE).

Besides several energy requirements reported there are equations to determine and to calculate the energy content of feeds (GfE, 1986–1998) and corresponding tables which include the nutritive values of feedstuffs for various species. The energy content of mixed feeds may be estimated by specific equations.     

An old paper revisited: "a mathematical model of carbohydrate energy metabolism. Interaction between glycolysis, the Krebs cycle and the H-transporting shuttles at varying ATPases load" by V.V. Dynnik, R. Heinrich and E.E. Sel'kov

We revisit an old Russian paper by V.V. Dynnik, R. Heinrich and E.E. Sel’kov (1980a, b) describing: “A mathematical model of carbohydrate energy metabolism. Interaction between glycolysis, the Krebs cycle and the H-transporting shuttles at varying ATPases load”. We analyse the model mathematically and calculate the control coefficients as a function of ATPase loads. We also evaluate the structure of the metabolic network in terms of elementary flux modes.We show how this model can respond to an ATPase load as well as to the glucose supply. We also show how this simple model can help in understanding the articulation between the major blocks of energetic metabolism, i.e. glycolysis, the Krebs cycle and the H-transporting shuttles.     

Vegetation patterns on Mount Everest as influenced by monsoon and föhn

The vegetation of Mt Everest is described by means of the dominant plant formations and characteristic features of biotopes. Climatic data givenin connection with weather observations show evidence that the extreme asymmetry of the altitudinal vegetation belt on the south and north slope is induced by heavy rainfall on the south slope and the desiccating effect of the Himalaya föhn in the valleys of the north slope. Biotope shift from hypsozonal distribution on the south slope to extrazonal distribution on the north slope is described, the patterns of the actual timber line are discussed in order to reconstruct the natural upper forest limit, and regressive plant successions during the last 400 years of man's impact are summarized. The dominant vegetation pattern of the alpine belt is compared with that in the European Alps. On the arid north slope alpine steppe communities occur up to 5 500 m. The highest altitudinal vegetation belt and the highest plant communities at 5 960 m are dominated by periglacial processes. The highest records of flowering plants (6 100/6 200 m) and lichens (7 400 m) are discussed in light of the present knowledge on high-altitude vegetation ecology.     

Untersuchungen Zur Energetischen Verwertung Von Rationen Mit Melasse,Getrockneten Zuckerrüben,Apfelpektin Und Luzerneblatt Durch Adulte Schweine

Abstract

Von 6 Rationen mit Melasse, getrockneten Zuckerrüben, Apfelpektin und Luzerneblatt wurde der Energieumsatz an 8 adulten Schweinen mittels Respirationsversuchstechnik gemessen. Die Verdaulichkeit der Energie der Rationen lag im Bereich von 74–88%, die partielle Verwertung der umsetzbaren Energie zwischen 66 und 78%. Aus den Versuchsergebnissen mit Apfelpektin wurde ein mittlerer Ansatzwert von 7,2 ± 12,5 kJ/g verdauliches Pektin abgeleitet. Unter Berücksichtigung der Literaturbefunde und der hohen Standardabweichungen wird für verdauliches Pektin ein energetischer Wirkungswert von 5 kJ/g für die Schätzung des energetischen Futterwertes (Nettoenergie-Fett) empfohlen.

STUDIES OF THE ENERGETIC UTILIZATION OF RATIONS WITH MOLASSES, DRIED SUGAR BEETS, APPLE PECTIN AND LUCERNE LEAVES IN ADULT PIGS

The energetic utilization of 6 rations with molasses, dried sugar beets, apple pectin and lucerne leaves was measured in 8 adult pigs by means of the respiration test technique. The energy digestibility of the rations ranged from 74 to 88%, the partial utilization of the metabolizable energy from 66 to 78%. From the results with apple pectin a mean energy deposition value of 7.2 ± 12.5 kJ/g digestible pectin was derived. Taking into consideration results from previous recorded experiments and the high standard deviation for estimation of the energetic feed value as deposition effect of digestible pectin, 5 kJ/g are proposed.     

特殊环境真菌

真菌是生物多样性最丰富和生存环境最多样的生物类群之一,除了我们熟知的土壤、植物残体、水体等一般环境外,还存在极地、高温、高盐等各种特殊环境.对真菌而言,特殊环境是指绝大多数真菌不能生存的环境,而特殊环境真菌是指特殊环境中特有的真菌或适应特殊环境的真菌.特殊环境人为地划分为以下3种类型:第一类,具有某种特定的理化限制因素的环境;第二类,某些特殊基质;第三类,受多因素限制的特殊复杂环境.特殊环境真菌有着独特的适应性,并进化出各种机制来占据生态位.它们在细胞构造、代谢方式、进化机制等方面的特殊性引起了科学家的广泛关注.本文介绍了各种特殊生态环境下生活的真菌类群以及它们的生存机制,并对今后的研究方向进行了展望.     

Sand as a medium for transmission of vibratory signals of prey in antlions Euroleon nostras (Neuroptera: Myrmeleontidae)

Abstract.  European pit-building antlions ( Euroleon nostras / Geoffroy in Fourcroy/) detect their prey by sensing the vibrations that prey generate during locomotory activity. The behavioural reactions and some of the physical properties of substrate vibrations in sand are measured to observe signal transmission through the substrate. The frequency range of the signals of four arthropod species ( Tenebrio molitor , Pyrrhocoris apterus , Formica sp. and Trachelipus rathkei ) is 0.1–4.5 kHz and acceleration values are in the range 400 μm s⁻² to 1.5 mm s⁻². Substrate particle size and the frequency of prey signals both influence the propagation properties of vibratory signals. The damping coefficient at a frequency 300 Hz varies from 0.26 to 2.61 dB cm⁻¹ and is inversely proportional to the size of the sand particle. The damping coefficient is positively correlated with the frequency of the pulses. Vibrations in finer sand are attenuated more strongly than in coarser sand and, consequently, an antlion detects its prey only at a short distance. The reaction distance is defined as the distance of the prey from the centre of the pit when the antlion begins tossing sand as a reaction to the presence of prey. The mean reaction distance is 3.3 cm in the finest sand (particle size ≤ 0.23 mm) and 12.3 cm in coarser sand (particle size 1–1.54 mm). The most convenient sands for prey detection are considered to be medium particle-sized sands.     

A Note on the Estimation of the Population Mean in Stratified Random Sampling Using Two Auxiliary Variables

In this paper, a two‐phase sampling estimator for a stratified population mean using two auxiliary variables x and z is considered when the stratum mean of x is unknown but that of z is known. The suggested estimator under its optimal condition is found to be more efficient than the one using only x.     

C<Subscript>1</Subscript> compounds as auxiliary substrate for engineered <Emphasis Type="Italic">Pseudomonas putida</Emphasis> S12

The solvent-tolerant bacterium Pseudomonas putida S12 was engineered to efficiently utilize the C₁ compounds methanol and formaldehyde as auxiliary substrate. The hps and phi genes of Bacillus brevis, encoding two key steps of the ribulose monophosphate (RuMP) pathway, were introduced to construct a pathway for the metabolism of the toxic methanol oxidation intermediate formaldehyde. This approach resulted in a remarkably increased biomass yield on the primary substrate glucose when cultured in C-limited chemostats fed with a mixture of glucose and formaldehyde. With increasing relative formaldehyde feed concentrations, the biomass yield increased from 35% (C-mol biomass/C-mol glucose) without formaldehyde to 91% at 60% relative formaldehyde concentration. The RuMP-pathway expressing strain was also capable of growing to higher relative formaldehyde concentrations than the control strain. The presence of an endogenous methanol oxidizing enzyme activity in P. putida S12 allowed the replacement of formaldehyde with the less toxic methanol, resulting in an 84% (C-mol/C-mol) biomass yield. Thus, by introducing two enzymes of the RuMP pathway, co-utilization of the cheap and renewable substrate methanol was achieved, making an important contribution to the efficient use of P. putida S12 as a bioconversion platform host.     

Mengen- und Spurenelementausnutzung durch Küken bei unterschiedlicher Vitamin-B6-Zufuhr

The need for improvement of feed information in future is discussed from the perspective for implementation in practice. Weaknesses of the current feed evaluation systems, energy systems in particular, are described: prediction of voluntary feed intake, additivity of digestibilities of individual feedstuffs and dynamics of digestion, efficiency of utilization of energy and variation in maintenance requirements. A brief inventory of models to quantify energy and nutrient metabolism by farm animals is followed by an overview of aspects required to fulfill the demands for a nutrient‐oriented feed evaluation. These include feed characteristics to determine and animal aspects, as well as involvement of environmental and management factors. The need for better harmonization of methods and quality of feed information and for international coordination in this matter is underlined.     

Two auxiliary variates in ratio method of estimation

A ratio type estimator using two auxiliary variates has been proposed and conditions are obtained to choose between proposed estimator and OLKIN'S (1958) estimator using two auxiliary variates.     

On Two Auxiliary Variates in Ratio Method of Estimation

A ratio type estimator using two auxiliary variates is suggested which is found to be more practicable than that of AGARWAL'S (1980) estimator.     

紫花苜蓿多元杂交后代优良株系筛选研究

通过对甘农3号、甘农5号和游客紫花苜蓿多元杂交后代选育的36个株系及其亲本的生长、产量、品质等相关指标的测定,采用灰色关联度理论,构造综合评价模型进行供试材料综合评价,筛选出速生12#、速生11#株系为最理想的优良株系,生长高度分别为105.44cm、105.42cm;生长速度分别为1.74cm/d、1.68cm/d;茎叶比分别为0.30、0.35;分枝数分别为23、17;鲜草产量分别为39.99 t/hm2、35.13 t/hm2;粗蛋白含量分别为19.95%、23.89%;相对饲用价值为153.15%、157.02%。多叶2#、速生5#、速生20#、速生21#等4个株系为较理想的优良株系。     

Water extraction of pyrolysis oil: the first step for the recovery of renewable chemicals

The interest in biomass as a source of renewable energy and chemicals has been increasing in keeping up with the transition to a sustainable bio-based economy. An important initial step of chemicals recovery from biomass-derived pyrolysis oil is water extraction where most of polar compounds are isolated in the aqueous phase. This study was done to investigate the effects of stirring rate and water-to-oil ratio on the extraction capability (distribution coefficient and yield), water content, and atomic composition of both aqueous and organic phases. The results show that the stirring rate above 300 rpm has no influence on the equilibrium. Increasing the water-to-oil ratio dilutes the aqueous phase without changing the atomic distribution. Forest residue-derived pyrolysis oil should be extracted at a water-to-oil ratio of 0.65-0.7, whereas pine-derived pyrolysis oil is preferably extracted at the lowest feasible water-to-oil ratio where complete phase separation occurs, which is 0.5 in this study.