Culture Conditions for the Production of l-Glutamic Acid from n-Paraffins by Glycerol Auxotroph GL-21

A novel process for the microbial production of l-glutamic acid on an industrial scale was successfully established by using a glycerol auxotroph.

The most suitable carbon source for producing L-glutamic acid was n-paraffins (C₁₃–C₁₅). The production of L-glutamic acid was not affected by a large amount of biotin or oleic acid in the absence of penicillin, and occurred maximally at the glycerol concentration of 0.02% at pH 6.6. The most effective temperature was 28°C.

Under optimal conditions in a 200 liter fermentor, the mutant produced 72 g/liter of L-glutamic acid. On the other hand, the parent produced 53 g/liter of L-glutamic acid in the presence of penicillin.

It is believed that the low productivity of L-glutamic acid by the parent strain was mainly due to the occurrence of the marked decrease in the viable cell counts at the later phase of the fermentation caused by the action of penicillin added.     

Programmed cell death during development of cowpea (Vigna unguiculata (L.) Walp.) seed coat

The seed coat develops primarily from maternal tissues and comprises multiple cell layers at maturity, providing a metabolically dynamic interface between the developing embryo and the environment during embryogenesis, dormancy and germination of seeds. Seed coat development involves dramatic cellular changes, and the aim of this research was to investigate the role of programmed cell death (PCD) events during the development of seed coats of cowpea [Vigna unguiculata (L.) Walp.]. We demonstrate that cells of the developing cowpea seed coats undergo a programme of autolytic cell death, detected as cellular morphological changes in nuclei, mitochondria, chloroplasts and vacuoles, DNA fragmentation and oligonucleosome accumulation in the cytoplasm, and loss of membrane viability. We show for the first time that classes 6 and 8 caspase‐like enzymes are active during seed coat development, and that these activities may be compartmentalized by translocation between vacuoles and cytoplasm during PCD events.     

Specific Secretion of Proline-Rich Proteins by Salt-Adapted Winged Bean Cells

Six proteins, designated SAP1 through SAP6, were secreted specificallyby salt-adapted cells of winged bean (Psophocarpus tetragonolobus)in suspension cultures. The amino-terminal amino acid sequencesof SAP2 (57 kDa), SAP4 (21 kDa), SAP5 (19 kDa) and SAP6 (17kDa) were homologous to the sequences of proline-rich proteins,indicating that proline-rich proteins are secreted specificallyby these salt-adapted cells. In addition, the amino-terminalamino acid sequence of SAP2 was identical to that of SAP4, andthe amino-terminal sequence of SAP5 was identical to that ofSAP6. Secretion of SAP2 was significantly enhanced by additionof AlCl₃ but not of KCl, LiCl, CaCl₂, MgCl₂, mannnitol or sucroseto suspension cultures. Furthermore, secretion of SAP4, SAP5and SAP6 was stimulated by addition of abscisic acid to cultures,suggesting that these proteins might be secreted in responseto salt or osmotic stress. (Received September 12, 1994; Accepted January 20, 1995)     

Effect of Ethylene on the Increase in Catalase Activity through Microbody Development in Wounded Sweet Potato Root Tissue

Catalase activity increases when slices of sweet potato roottissue are incubated in air. The increase is due to de novosynthesis of the enzyme protein and probably also to activationof a precursor protein [Esaka et al. (1983) Plant & CellPhysiol. 24: 615]. The activity-increase was partly depressedwhen tissue slices were incubated in ethylenecontaining air,while the immunologically determined amount of catalase proteindid not increase, rather it decreased, under the same conditions.We propose that ethylene inhibits the de novo synthesis of catalaseprotein but not the activation of precursor protein. Catalasefrom tissue slices incubated in ethylene-containing air migratedfaster on a polyacrylamide gel than that from intact tissueor tissue slices incubated in air. When either polyacrylamideor an SDS-polyacrylamide gel applied with crude extract fromtissue slices incubated in ethylene-containing air underwentimmunological blotting, the blots were much fainter than thosefor intact tissue. In addition, microbody membrane fractionfrom incubated tissue slices contained a significant amountof catalase which was sedimented at the bottom of a sucrosedensity gradient (20–70%) and was not solubilized by highconcentrations of lubrol PX. The fraction showed an exceptionallyhigh catalase activity per unit amount of immunoreactive proteinto anti-catalase antibody. We propose that ethylene causes somemodification of catalase protein which facilitates the formationof aggregates or cores. ¹Present address: Laboratory of Food Technology, Faculty ofApplied Biological Science, Hiroshima University, Fukuyama,Hiroshima 720, Japan. ²Present address: Terumo Co. Ltd., Omiya, Fujinomiya, Shizuoka418, Japan. (Received October 16, 1982; Accepted February 24, 1983)     

Staging and the time course of embryonic development in kurosoi,Sebastes schlegeli

Synopsis Intraovarian development of embryos was observed in 31 female rockfish kurosoi,Sebastes schlegeli, which had been raised in the laboratory. Three of the females had newly fertilized eggs; the others' embryos were at various stages. The developmental series (33 stages) was not very different from that in oviparous fishes. However, several characteristic features were noted: thin egg envelope, narrow perivitelline space, elliptical encapsulated embryo in the late stages and depletion of yolk at parturition. The time course of development up to birth at different temperatures was adjusted to that at 9.8°C using the Arrhenius equation and processed for the relationship between the stage number (X) and stage-to-birth time in days (Y). An equation, was obtained, and the gestation period was calculated to be 48 days at 9.8°C.     

Quantification of genetically modified soybeans using a combination of a capillary-type real-time PCR system and a plasmid reference standard

Because the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved genetically modified varieties in many countries, there is a need for a rapid and useful method of GMO quantification in food samples. In this study, a rapid detection system was developed for Roundup Ready Soybean (RRS) quantification using a combination of a capillary-type real-time PCR system, a LightCycler real-time PCR system, and plasmid DNA as the reference standard. In addition, we showed for the first time that the plasmid and genomic DNA should be similar in the established detection system because the PCR efficiencies of using plasmid DNA and using genomic DNA were not significantly different. The conversion factor (Cf) to calculate RRS content (%) was further determined from the average value analyzed in three laboratories. The accuracy and reproducibility of this system for RRS quantification at a level of 5.0% were within a range from 4.46 to 5.07% for RRS content and within a range from 2.0% to 7.0% for the relative standard deviation (RSD) value, respectively. This system rapidly monitored the labeling system and had allowable levels of accuracy and precision.     

Secretion of basic and acidic chitinases from salt-adapted and -unadapted winged bean cells

Northern hybridizations were used to study the site of synthesis of three carboxypeptidases (Cpases I-III) which occur in the starchy endosperm of germinating barley grain ( Hordeum vulgare L.). Further evidence was obtained by studying secretion of these enzymes from scutella or aleurone layers separated from germinating grains. Messenger RNA for Cpase II was detected only in developing grain, and the bulk of the mRNA was localized in the starchy endosperm. This suggests that Cpase II is synthesized at the site of its accumulation, the starchy endosperm. In contrast, Cpase I is expressed during germination and the predominant site of synthesis is the scutellum, from which it is secreted into the starchy endosperm. Cpase III is also synthesized during germination, but the bulk of it is synthesized in and secreted from the aleurone layer. Thus, the three carboxypeptidases, all of which seem to play a role in hydrolysis of the reserve proteins in the starchy endosperm during germination, have different sites of synthesis.     

Induction of Polysome Formation in Sweet Potato Root Tissue in Response to Wounding

We determined the effects of yolk water-soluble protein (YSP) on bone resorption. YSP potently suppressed osteoclastogenesis from bone marrow-derived precursor cells driven by tumor necrosis factor-α (TNF-α). YSP (200 μg/ml) abolished the formation of tartarate-resistant acid phosphatase (TRAP)-positive osteoclasts. Furthermore, TNF-α induced TRAP activity was greatly inhibited by YSP (100 μg/ml) treatment. Our results suggest that YSP has therapeutic potential for bone-erosive diseases.     

Reproductive system,social organization,human disturbance and ecological dominance in native populations of the little fire ant,Wasmannia auropunctata

The invasive ant species Wasmannia auropunctata displays both ecologically dominant and non‐dominant populations within its native range. Three factors could theoretically explain the ecological dominance of some native populations of W. auropunctata: (i) its clonal reproductive system, through demographic and/or adaptive advantages; (ii) its unicolonial social organization, through lower intraspecific and efficient interspecific competition; (iii) the human disturbance of its native range, through the modification of biotic and abiotic environmental conditions. We used microsatellite markers and behavioural tests to uncover the reproductive modes and social organization of dominant and non‐dominant native populations in natural and human‐modified habitats. Microsatellite and mtDNA data indicated that dominant and non‐dominant native populations (supercolonies as determined by aggression tests) of W. auropunctata did not belong to different evolutionary units. We found that the reproductive system and the social organization are neither necessary nor sufficient to explain W. auropunctata ecological dominance. Dominance rather seems to be set off by unknown ecological factors altered by human activities, as all dominant populations were recorded in human‐modified habitats. The clonal reproductive system found in some populations of W. auropunctata may however indirectly contribute to its ecological dominance by allowing the species to expand its environmental niche, through the fixation over time of specific combinations of divergent male and female genotypes. Unicoloniality may rather promote the range expansion of already dominant populations than actually trigger ecological dominance. The W. auropunctata model illustrates the strong impact of human disturbance on species’ ecological features and the adaptive potential of clonal reproductive systems.