Language trees ≠ gene trees

Darwin saw similarities between the evolution of species and the evolution of languages, and it is now widely accepted that similarities between related languages can often be interpreted in terms of a bifurcating descent history (‘phylogenesis’). Such interpretations are supported when the distributions of shared and unshared traits (for example, in terms of etymological roots for elements of basic vocabulary) are analysed using tree-building techniques and found to be well-explained by a phylogenetic model. In this article, we question the demographic assumption which is sometimes made when a tree-building approach has been taken to a set of cultures or languages, namely that the resulting tree is also representative of a bifurcating population history. Using historical census data relating to Gaelic- and English-speaking inhabitants of Sutherland (Highland Scotland), we have explored the dynamics of language death due to language shift, representing the extreme case of lack of congruence between the genetic and the culture–historical processes. Such cases highlight the important role of selective cultural migration (or shifting between branches) in determining the extinction rates of different languages on such trees.     

Submerged culture of chromium-enriched Termitomyces albuminosus

A species of mushroom, Termitomyces albuminosus, was cultured in liquid medium for production of chromium-enriched mycelium. The influence of chromium （Ⅲ） on mycelial growth of T. albuminosus was investigated. An optimum medium composed of 5.6g/L yeast extract, 51.6g/L hydrolyzed rice, 2g/L KH2PO4, and 20mg/L chromium（Ⅲ） with initial pH of 4.5 was obtained by using method of central composite design （CCD）. After incubation of 84h, the maximal biomass of chromium-enriched mycelia reached 24.23g DMW（dried mycelial weight）/L with 272μg/g DMW chromium content in 500mL flasks containing 100mL medium with an inoculum of 8% on a shaker of 100r/min under an optimized cultivation condition at 28 ℃.     

Approaches to valuing plant medicines: the economics of culture or the culture of economics?

This paper explores the scope and limitations of the economic valuation of biodiversity. How and why is this a useful exercise, but in what way is its usefulness constrained? These issues are discussed with particular reference to cultural values within the context of medicinal plants and phytopharmaceutical development. It is argued that whilst economic valuation is an extremely important and necessary aid to formulating conservation policy, it probably is not that informative about the motivations of people in their use of certain natural resources. This is especially true for the case of medicinal plants where belief systems about the causes of disease and therefore strategies for healing are important. The paper reviews studies which have attempted to put monetary values on medicinal plants and the option values of pharmaceuticals developed from plants, and discusses the applicability of the various approaches. The implications for conservation policy, and for likely collaboration between social and natural scientists is discussed.     

Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production

Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l^?1 sucrose, 0.5 mg l^?1 of the auxin 1-naphthalene acetic acid, and 0.5 mg l^?1 of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230 %) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.     

Carved trees in grazed forests in boreal Sweden—analysis of remaining trees, interpretation of past land-use and implications for conservation

Culturally modified trees (CMTs) provide unique insights into traditional knowledge and uses of the forest ecosystems. In close relation to pre-industrial livestock herding in central Sweden, it was a custom to carve text and symbols on trees and use them as notice boards in the forest. The main aim of this study was to document and analyse remaining carved trees in a managed forest landscape of 160 km². The same area was surveyed twice, once in 1986 and once in 2003. 488 carved trees were documented and classified into legible themes that were interpreted in the light of past herding practices. Name was the most common theme, found in 85% of the carvings. Most of the carvings were made in the period from the 1750s until the early 1900s. The custom of carving on trees was closely related to important grazing areas and the need to establish rights to them. The main losses of carved trees nowadays are due to their natural death and decay as most of the carved trees are located in areas that are not targeted for management. A primary recommendation for preservation is therefore to continue documentation of the trees because of the noticeable deterioration in readability of the carvings.     

Knots in trees – A new rich source of lignans

Recent research in our group has revealed that knots, i.e. the branch bases inside tree stems, commonly contain 5–10% (w/w) of lignans. Norway spruce (Picea abies) knots contain as much as 6–24% of lignans, with 7-hydroxymatairesinol (HMR) as the predominant (70–85%) lignan. Some other spruce species also contain HMR as the main lignan, but some spruce species have also other dominating lignans. Most fir (Abies) species contain secoisolariciresinol and lariciresinol as the main lignans. Lignans occur also in knots of pines (Pinus spp.), although in lower amounts than in spruces and firs. Scots pine (Pinus silvestris) knots were found to contain 0.4–3% of lignans with nortrachelogenin as the main lignan. Lignans have been identified also in knots of some hardwoods, although flavonoids are more abundant in hardwoods. Knots are detrimental in the manufacture of pulp and paper and should preferably be removed before pulping. This is possible using a recently developed industrially applicable process called ChipSep. Recent research has also established novel synthetic routes to several lignans, such as matairesinol, secoisolariciresinol, lariciresinol and cyclolariciresinol, starting from hydroxymatairesinol by applying fairly straight-forward chemical transformations. We conclude that wood knots in certain spruce and fir species constitute the richest known source of lignans in nature. The lignans occur in knots in free form and are easily extracted by aqueous ethanol, or even by water. Not only HMR, but also other potentially valuable lignans, could be produced in a scale of hundreds of tons per year by extraction of knots separated from wood chips at pulp and paper mills.     

Identification of chilling and heat requirements of cherry trees—a statistical approach

Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. ‘Schneiders späte Knorpelkirsche’ trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. ‘Schneiders späte Knorpelkirsche’ cherries at Bonn exhibited a chilling requirement of 68.6?±?5.7 chill portions (or 1,375?±?178 chilling hours or 1,410?±?238 Utah chill units) and a heat requirement of 3,473?±?1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package (‘chillR’) and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. ‘Payne’) at Davis, California.     

Drip nitrogen fertigation of ‘Starking Delicious’ apple trees

The response of ‘Starking Delicious’ (Malus domestica Borkh.) apple trees to four N fertigation treatments in drip irrigation (50, 150, 250 and 400 kg N ha⁻¹, supplemented with a uniform dose of 400 kg K ha⁻¹) was investigated in a field experiment during 6 years. Nitrate nitrogen in the soil was proportional (7–58 mg kg⁻¹) to the applied N dose at the end of a 6 week fertigation period in the spring. At other times, the nitrate concentration in the soil was very low. Soil K decreased with depth and in the 0–30 cm soil layer it was negatively correlated with the applied N dose, before fertigation started. At the end of the spring fertigation period, higher K was found in all soil layers analyzed. Vegetative growth was correlated positively with the amount of N applied. Leaf chlorophyll and N were significantly lower only in the lowest N treatment, while increased fruit size and decreased fruit color were measured only in the higher N treatments. Yield was severely biennial. In the ‘On’ years crop load was heavier as less N was applied. An extremely high crop load in the lowest N treatment was followed by a reduced flower density and yield in the following season. In the ‘Off’ years, a significantly higher yield was obtained with the 150 kg ha⁻¹ dose. The dry weights, N, P and K contents of the above ground parts of mature apple trees were determined. Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 2342-E, 1988 Series.     

Behaviour in culture of isolated protoplasts from “Paul's scarlet” rose suspension culture cells

Summary Protoplasts were enzymatically isolated from Paul's scarlet rose suspension culture cells. They were cultured in medium similar to that used to culture the cells from which they were isolated with the addition of sucrose as an osmotic stabiliser. They were studied by light and electron microscopy and their changes in size and number per culture were recorded. Expansion was greater when the protoplasts were cultured in medium plus 12% sucrose than with 24% sucrose. Budding was observed. In medium plus 12% sucrose about 45% of the protoplasts divided but in medium plus 24% sucrose far fewer divided. Cytokinesis was abnormal: the phragmoplast disappeared soon after cytokinesis began and the cell plate became a groove and then a fibril-lined or filled tongue which progressed across the vacuole, unconnected by strands to other parts of the protoplast. The wall regenerated after several days culture in medium plus 12% sucrose fluoresced with calcofluor. The wall regenerated in medium with 24% sucrose fluoresced usually only after several weeks culture. Cytokinesis hastened formation of a wall fluorescing with calcofluor. In the electron microscope the wall was seen to contain fibrils and non-fibrillar material. The latter was the minor component in medium plus 12% sucrose but was usually the major component in medium plus 24% sucrose. The growth in plasmolysing and nonplasmolysing medium of the cells from which protoplasts are isolated was also studied.It appears that loss of the wall alters the potential of protoplasts to expand and possibly also to regenerate a wall and to divide. Wall regeneration is initially linked with expansion and cytokinesis. Osmotic pressure of the external medium is also an important factor.This work formed part of a thesis by one of us (R.S.P.) approved for the degree of Ph. D. in the University of Nottingham. The work was supported by the Agricultural Research Council.     

Production of poly-β-hydroxybutyrate by fed-batch culture of recombinantEscherichia coli

Summary A recombinantEscherichia coli strain harboring the PHB biosynthesis genes fromAlcaligenes eutrophus was used to produce poly--hydroxybutyrate (PHB) by pH-stat fedbatch culture. Initial glucose concentration for optimal growth was found to be 20g/L from a series of flask cultures. A final PHB concentration of 88.8 g/L could be obtained after 42 hrs of cultivation.     

Validation of the BacT/ALERT?3D automated culture system for the detection of microbial contamination of epithelial cell culture medium

Living tissue engineering for regenerative therapy cannot withstand the usual pharmacopoeia methods of purification and terminal sterilization. Consequently, these products must be manufactured under aseptic conditions at microbiologically controlled environment facilities. This study was proposed to validate BacT/ALERT(?)3D automated culture system for microbiological control of epithelial cell culture medium (ECCM). Suspensions of the nine microorganisms recommended by the European Pharmacopoeia (Chap. 2.6.27: "Microbiological control of cellular products"), plus one species from oral mucosa and two negative controls with no microorganisms were prepared in ECCM. They were inoculated in FA (anaerobic) and SN (aerobic) culture bottles (Biomérieux, Lyon, France) and incubated in a BacT/ALERT(?)3D automated culture system. For each species, five sets of bottles were inoculated for reproducibility testing: one sample was incubated at the French Health Products Agency laboratory (reference) and the four others at Cell and Tissue Bank of Lyon, France. The specificity of the positive culture bottles was verified by Gram staining and then subcultured to identify the microorganism grown. The BacT/ALERT(?)3D system detected all the inoculated microorganisms in less than 2 days except Propionibacterium acnes which was detected in 3 days. In conclusion, this study demonstrates that the BacT/ALERT(?)3D system can detect both aerobic and anaerobic bacterial and fungal contamination of an epithelial cell culture medium consistent with the European Pharmacopoeia chapter 2.6.27 recommendations. It showed the specificity, sensitivity, and precision of the BacT/ALERT(?)3D method, since all the microorganisms seeded were detected in both sites and the uncontaminated medium ECCM remained negative at 7 days.     

Increased production of cloned β-galactosidase in two-stage culture of Bacillus amyloliquefaciens

Bacillus amyloliquefaciens harboring recombinant plasmid pHG5, which encodes B. stearothermophilus β-galactosidase, was cultured in a jar fermentor. By feeding lactose a considerable concentration of the enzyme was produced, but the cells stopped growing at an OD₆₆₀ of about 30. On the other hand, the microorganism grew to a very high cell concentration with an OD₆₆₀ of around 110 with glucose as a carbon source, but the enzyme specific activity was a half of the maximum value with lactose. Based on these facts, B. amyloliquefaciens was first grown using glucose, and the carbon source was then switched to lactose to induce β-galactosidase production. By this two-step culture method, both good cell growth and high enzyme productivity were obtained.     

Starter culture for the production of ‘soyiru’

Bacillus subtilis or licheniformis facilitated production of soyiru with the best results being given by using both together. Fermentation employing Streptococcus enterococcus was unsuccessful.H.A. Suberu is with the Department of Biological Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria. J.A. Akinyanju is with the Department of Biological Sciences, University of Ilorin, P.M.B. 1515, Ilorin, Nigeria.     

Improvement of intracellular β-galactosidase production in fed-batch culture of Kluyveromyces fragilis

Four fed-batch control strategies were evaluated to improve the specific lactase activity of Kluyveromyces fragilis. Control strategies tested included DO-stat control, exponential feeding, exponential feeding with manual feedback control and corrected feed-forward control. Each was implemented with standard sensors (i.e., temperature, dissolved oxygen and pH sensors) commonly installed in fermenters. The highest specific activity was obtained using the corrected feed-forward control strategy, a strategy incorporating a novel method for on-line estimation of specific growth rate. The control strategy was able to operate effectively to a final cell density of 69 g dry wt l^–1 with a specific lactase activity of 2 U mg^–1 cell dry wt.     

Enhancement of productivity of recombinant α-amidating enzyme by low temperature culture

We have produced a recombinant C-terminal α-amidating enzyme (799BglIIα-AE) derived from Xenopus laevis by culturing a CHO cell line named 3μ-1S. Recently, we demonstrated that culturing 3μ-1S cells at a temperature below 37 °C led to the following phenomena: inhibited cell growth with high viability, enhanced cellular productivity (maximally at 32 °C), and suppressed medium consumption and release of impurities from the cells. Therefore, it is suggested that the 799BglIIα-AE production will be increased by culturing a sufficient number of the cells at a low temperature (especially at 32 °C). To assess this effect on batch and perfusion cultures, the culture temperature was shifted from 37 to 32 °C in the mid-exponential phase in the case of batch culture and from 37 to 34 °C when the cell density became high enough in the case of perfusion culture. Application of the low temperature culture to batch and perfusion cultures was effective in comparison with the culture at 37 °C: the productivity per medium and the productivity per time were increased severalfold with enhanced cellular productivity at a low culture temperature. The low temperature culture also increased the relative content of 799BglIIα-AE in the supernatant and reduced the glucose consumption. The method presented here would contribute to production of bioactive proteins using other recombinant cell lines. This revised version was published online in August 2006 with corrections to the Cover Date.