Production of 1,3-propanediol by Clostridium butyricum VPI 3266 using a synthetic medium and raw glycerol

Growth inhibition of Clostridium butyricum VPI 3266 by raw glycerol, obtained from the biodiesel production process, was evaluated. C. butyricum presents the same tolerance to raw and to commercial glycerol, when both are of similar grade, i.e. above 87% (w/v). A 39% increase of growth inhibition was observed in the presence of 100 g l 1 of a lower grade raw glycerol (65% w/v). Furthermore, 1,3-propanediol production from two raw glycerol types (65% w/v and 92% w/v), without any prior purification, was observed in batch and continuous cultures, on a synthetic medium. No significant differences were found in C. butyricum fermentation patterns on raw and commercial glycerol as the sole carbon source. In every case, 1,3-propanediol yield was around 0.60 mol/mol glycerol consumed

Production of 1,3-Propanediol by Clostridium butyricum VPI 3266 in continuous cultures with high yield and productivity

The effects of dilution rate and substrate feed concentration on continuous glycerol fermentation by Clostridium butyricum VPI 3266, a natural 1,3-propanediol producer, were evaluated in this work. A high and constant 1,3-propanediol yield (around 0.65 mol/mol), close to the theoretical value, was obtained irrespective of substrate feed concentration or dilution rate. Improvement of 1,3-propanediol volumetric productivity was achieved by increasing the dilution rate, at a fixed feed substrate concentration of 30, 60 or 70 g l-1. Higher 1,3-propanediol final concentrations and volumetric productivities were also obtained when glycerol feed concentration was increased from 30 to 60 g l-1, at D=0.05–0.3 h-1, and from 60–70 g l-1, at D=0.05 and 0.1 h-1. 30 g l-1 of 1,3-propanediol and the highest reported value of productivity, 10.3 g l-1 h-1, was achieved at D=0.30 h-1 and 60 g l-1 of feed glycerol. A switch to an acetate/butyrate ratio higher than one was observed for 60 g l-1 of feed glycerol and a dilution rate higher than 0.10 h-1; moreover, at D=0.30 h-1 3-hydroxypropionaldehyde accumulation was observed for the first time in the fermentation broth of C. butyricum

1,3-Propanediol production in a two-step process fermentation from renewable feedstock

In this work, the production of 1,3-propanediol from glucose and molasses was studied in a two-step process using two recombinant microorganisms. The first step of the process is the conversion of glucose or other sugar into glycerol by the metabolic engineered Saccharomyces cerevisiae strain HC42 adapted to high (>200 g l−1) glucose concentrations. The second step, carried out in the same bioreactor, was performed by the engineered strain Clostridium acetobutylicum DG1 (pSPD5) that converts glycerol to 1,3-propanediol. This two-step strategy led to a flexible process, resulting in a 1,3-propanediol production and yield that depended on the initial sugar concentration. Below 56.2 g l−1 of sugar concentration, cultivation on molasses or glucose showed no significant differences. However, at higher molasses concentrations, glycerol initially produced by yeast could not be totally converted into 1,3-propanediol by C. acetobutylicum and a lower 1,3-propanediol overall yield was observed. In our hand, the best results were obtained with an initial glucose concentration of 103 g l−1, leading to a final 1,3-propanediol concentration of 25.5 g l−1, a productivity of 0.16 g l−1 h−1 and 1,3-propanediol yields of 0.56 g g−1 glycerol and 0.24 g g−1 sugar, which is the highest value reported for a two-step process. For an initial sugar concentration (from molasses) of 56.2 g l−1, 27.4 g l−1 of glycerol were produced, leading to 14.6 g l−1 of 1.3-propanediol and similar values of productivity, 0.15 g l−1 h−1, and overall yield, 0.26 g g−1 sugar.info:eu-repo/semantics/acceptedVersio

State of exploitation of the black seabream, Spondyliosoma cantharus (Linnaeus, 1758), off Gran Canaria (Canary Islands)

En el presente trabajo se evalúa el estado de explotación de la chopa Spondyliosoma cantharus (L., 1758) en aguas de Gran Canaria (islas Canarias) mediante el análisis de cohortes sobre distribuciones de tallas. Para llevar a cabo el análisis se dispuso de 30 068 ejemplares procedentes de pescas comerciales realizadas entre enero de 1994 y diciembre de 1996. La chopa, especie común en las capturas demersales efectuadas por la flota artesanal en Gran Canaria, se pesca principalmente con nasa y, de forma ocasional, con palangre. Las tallas de los individuos capturados están comprendidas entre 8 y 40 cm de longitud total. La nasa incide sobre ejemplares de todas las clases de tallas, principalmente de 20-22 cm, y el palangre sobre ejemplares de 20 a 40 cm, principalmente de 24-26 cm. La estrategia de pesca actual genera una situación de sobrepesca en crecimiento. Un cambio en el esquema, basado en la reducción de la mortalidad pesquera para la nasa, incrementaría de manera significativa el rendimiento y la biomasa de reproductores.The study examines the state of exploitation of the black seabream, Spondyliosoma cantharus (L., 1758), off Gran Canaria (Canary Islands) using a length cohort analysis based on data from 30 068 individuals obtained from commercial catches between January 1994 and December 1996. The black seabream, a common species in the demersal catches of the artisanal Gran Canaria fishery, is mainly captured with traps, and occasionally with longlines. Total length of individuals ranged from 8 cm to 40 cm. Specimens from the subgroup caught by traps ranged from 8 cm to 40 cm, but were mostly 20-22 cm; the longline subgroup ranged from 20 cm to 40 cm, with most individuals measuring 24-26 cm. The current fishery strategy produces a situation of overexploitation; a change, reducing fishing mortality resulting from trap use, would significantly increase both the yield and the spawning stock biomass.Instituto Español de Oceanografí

Reproductive biology of the sand smelt Atherina presbyter Cuvier, 1829 (Atherinidae) off Gran Canaria (Canary Islands)

Se estudiaron 1 028 ejemplares de guelde blanco Atherina presbyter Cuvier, 1829 capturados alrededor de la isla de Gran Canaria (islas Canarias) durante el periodo comprendido entre julio de 1995 y junio de 1996. Las tallas oscilaron entre 14,6 mm y 115,5 mm de longitud total. La proporción entre sexos no presentó diferencias significativas con la relación teórica 1:1. El periodo reproductor se situó entre febrero y junio, con un máximo de actividad gonadal en abril-mayo. Las tallas medias de primera maduración y de maduración masiva se alcanzaron, respectivamente, a los 67,7 mm y 94,9 mm en los machos y a los 65,3 mm y 92,6 mm en las hembras; tampoco en estos valores medios las diferencias entre los dos sexos se mostraron estadísticamente significativas.Sand smelt Atherina presbyter Cuvier 1829 (N = 1 028) caught off Gran Canaria (Canary Islands) between July 1995 and June 1996 were studied. The size range was 14.6 mm to 115.5 mm total length. The ratio of males to females was not significantly different from 1:1. The reproductive period extended from February to June, with an April-May peak in spawning activity. Mean total lengths at 50 % and 95 % maturity were 67.7 mm and 94.9 mm for males, and 65.3 mm and 92.6 mm for females, although these different values between the sexes were not statistically significant.Instituto Español de Oceanografí

Growth of the chub mackerel Scomber japonicus (Houttuyn, 1782) off the Canary Islands determined by length-frequency analysis

The growth of the chub mackerel Scomber japonicus (Houttuyn, 1782) off the Canary Islands was determined by length-frequency analysis. The total length was measured in 3858 individuals captured south-west of Gran Canaria (Canary lslands) from March 1988 to July 1990. The length range was wide (13-48 cm total length) and the frequencies were very variable. The class modes, identified by using the method of Bhattacharya (1967), corresponded to the age-groups 0-5 years. The value of the theoretical maximum length obtained by means of the method of Wetherall, Polovina and Ralston (1987) was 47.3 cm. The values of the parameters of the seasonally oscillating Von Bertalanffy growth equation, determined by the method of Pauly and David (I981), were L∞= 49.50 cm, k = 0.23 year˄-1, C = 0.650 and WP = 0.800. The length frequency analysis provided very satisfactory results for the Canary Islands chub mackerel. These results were very similar to those obtained by reading otoliths.Se determinó el crecimiento de la caballa Scomber japonicus (Houttuyn, 1782) de las islas Canarias a través del análisis de las frecuencias de tallas. La longitud total fue medida en 3858 ejemplares capturados al suroeste de Gran Canaria (islas Canarias) entre los meses de marzo de 1988 y julio de 1990. El rango de tallas fue amplio (13-48 cm de longitud total) y su abundancia relativa variable. Las tallas modales discriminadas mediante el método de Bhattacharya (1967) correspondieron a los grupos de edad de 0 a 5 años. El valor de la longitud máxima teórica, obtenida por aplicación del método de Wetherall, Polovina y Ralston (1987), fue 47,3 cm. Los valores de los parámetros de la ecuación de crecimiento estacional oscilatorio de Von Bertalanffy, obtenidos por el método de Pauly y David (1981), fueron L∞= 49,50 cm, k = 0,23 año˄-1, C = 0,650 y W = 0,800. Los métodos de análisis de frecuencia de tallas ofrecieron resultados muy satisfactorios para la caballa de las islas Canarias. Dichos resultados fueron muy similares a los obtenidos por lectura directa de los otolitos.Instituto Español de Oceanografí

New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)

As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.Postprin

Sexuality and reproduction of annular seabream Diplodus annularis (L., 1758) (Pisces, Sparidae) off Gran Canaria (Canary Islands)

A study on the sexuality and reproduction of annular seabream Diplodus annularis (L., 1758) was conducted, based on data from 792 individuals caught off Gran Canaria (Canary Islands) between January 1998 and December 1999. The size range was 79 mm to 209 mm total length. The sexual type is proterandric hermaphroditism. Males were more abundant than females (1:0.78) in the sample, with males predominating in smaller size intervals, and females in larger ones. The spawning period extended from February to May, with a peak in March-April. The length at first maturity was 102 mm for males, and 126 mm for females.Se estudia la sexualidad y la reproducción en 792 ejemplares de raspallón Diplodus annularis (L., 1758) capturados en aguas de la isla de Gran Canaria (islas Canarias) entre enero de 1998 y diciembre de 1999. El rango de tallas oscila entre 79 y 209 mm de longitud total. El tipo sexual es hermafroditismo proterándrico. Los machos son más abundantes que las hembras (1:0,78) y predominan en las tallas inferiores; las hembras prevalecen en las superiores. El periodo reproductor se extiende desde febrero hasta mayo, con un máximo de actividad en marzo-abril. La talla de primera madurez se alcanza a los 102 mm en los machos y a los 126 mm en las hembras.Instituto Español de Oceanografí

New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)

As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.S