Enhanced production of pigment-free pullulan by a morphogenetically arrested Aureobasidium pullulans (ATCC 42023) in a two-stage fermentation with shift from soy bean oil to sucrose

A two-stage fermentation process was established for the production of pigment-free pullulan by the yeast-like fungus Aureobasidium pullulans (ATCC 42023). In the first stage, starting at pH 4.5 with soy bean oil as the carbon source and glutamate as the nitrogen source, a cell mass of about 15 g l^–1 dry cell weight was obtained, the population being restricted mainly to the yeast form of the microorganism (yeast form more than 90% of total cells) and the formation of pigment in the culture being prevented. Small amounts of pullulan (less than 2 g l^–1) are produced at this phase, and the viscosity remained low throughout the entire growth stage. When the oil and glutamate source were nearly exhausted (below 5% of initial amounts), the cells were shifted to a production stage with sucrose as the carbon source with continued nitrogen depletion. Production of pullulan started immediately with no lag period. During 50 h of the production phase more than 35 g l^–1 of pullulan was produced (productivity approx. 0.7 g l^–1), resulting in a large increase in the viscosity of the broth. The production yield of pollulan on the sugar was about 0.6 g g^–1. Morphogenesis from the yeast form of the microorganism to chlamydospores was still restrained and no pigment was formed in the culture during the production stage. A pigment-free polysaccharide, with a molecular mass in the range of 600–750 kDa, was recovered from the supernatant of the broth after solvent precipitation.     

The Lepocreadiidae (Digenea) of fishes from the north-east Atlantic: a review of the genusLepidapedon Stafford, 1904

The genusLepidapedon is subdivided into several species groups and subgroups of species based on the vitelline distribution and the length of the excretory vesicle. The species in each of the subgroups are listed and keys to the species in most subgroups are given. The following north-eastern Atlantic species are described or redescribed:Lepidapedon rachion fromMelanogrammus aeglefinus, Gadus morhua, Aspitrigla cuculus, Merlangius merlangus andPollachius pollachius; L. cambrensis fromEnchelyopus cimbrius; L. sommervillae n. sp. fromTrachyrincus scabrus, T. murrayi andCoryphaenoides guentheri; L. elongatum fromGadus morhua; L. gaevskayae fromCoryphaenoides (Nematonurus) armatus; L. discoveryi n. sp. fromCoryphaenoides (Nematonurus) armatus; L. arlenae n. sp. fromTrachyrincus scabrus andT. murrayi; L. mariannae n. sp. fromGaidropsarus argentatus; Lepidapedon spp. innom (Elongatum-group) fromCoryphaenoides guentheri andCoryphaenoides (Chalinura) leptolepis; L. desclersae n. sp. fromLepidion eques; L. beveridgei fromCoryphaenoides (Nematonurus) armatus andC. (Chalinura) mediterraneus; andL. zubchenkoi fromCoryphaenoides (Chalinura) leptolepis andC. (C.) profundicolus. The phylogeny, host-specificity and zoogeography of the genus are briefly discussed.     

REPRODUCTION AND RECRUITMENT OF NUCULOMA TENUIS (BIVALVIA: NUCULOIDA) FROM LOCH ETIVE, SCOTLAND

A population of the protobranch bivalve Nuculoma tenuis at adepth of c. 54 m in Loch Etive, West Scotland, was sampled monthlyfrom September 1986 to October 1988. The density of N. tenuisin the samples, and the relative proportions of adults and postlarvae,varied markedly from month to month suggesting patchiness atthe scale of the sampling. There was evidence for spatial segregationof adults and postlarvae. A seasonal reproductive cycle occurred,with a synchronised spawnout in winter; the exact timing appearingto vary in successive years by up to 2 months. Despite markedlyseasonal spawning, no recruitment peak was evident in shell-lengthfrequencies, and benthic postlarvae were present throughoutthe year. This corroborates findings from an earlier laboratorystudy, suggesting a prolonged phase of meiobenthic developmentin this species. (Received 1 February 1995; accepted 15 March 1995)     

4-phenylylboronic acid: A new type of enhancer for the horseradish peroxidase catalysed chemiluminescent oxidation of luminol

4-Phenylylboronic acid enhances the light emission from the horseradish peroxidase catalysed oxidation of luminol by hydrogen peroxide. Optimization studies showed that the greatest enhancement was obtained using micromolar concentrations of the new enhancer. The largest degree of enhancement was found with the basic isoenzyme of horseradish peroxidase (Type VIA), and lesser degrees of enhancement were obtained with Type VII and Type IX horseradish peroxidase. The enhancer was also effective in the peroxidase catalysed oxidation of isoluminol by peroxide.     

Heterochromatin and cytogenetic polymorphisms in Cebus apella (Cebidae,Platyrrhini)

Cytogenetic studies have been carried out in 39 specimens of C. apella of different origins. Three different morphologies, one affecting the long arm of chromosome 4 and two affecting pair 17, have been detected. In each case, they can be related by paracentric inversions. Heterochromatin polymorphisms affecting terminal or interstitial C+ regions have also been observed. The length of the terminal heterochromatic region in the long arms of chromosome 11 is variable in C. apella sp., in C. a. paraguayanus and absent in the C. a. nigritus specimens studied. Interstitial C + bands can be observed in the long arms of the biarmed chromosomes 4 and 6, and in the long arms of the acrocentric pairs 12, 13, 17, 18, 19, 20, and 21. Interstitial C + bands in the long arms of chromosomes 4, 12, 17, and 19 are present in all animals studied, although their size is variable, especially in the case of chromosomes 17 and 19. © 1995 Wiley-Liss, Inc.