Distribution of heterotrophic aerobic marine bacteria in sediment in Eastern Harbour of Alexandria

Abstract

In Eastern Harbour (EH) of Alexandria (Egypt), where an under-water museum is planned to be built, the distribution of some heterotrophic bacteria and their relationships to physical parameters and biochemical composition of the sedimentary organic matter were investigated. The Eastern Harbour is a relatively shallow semi-closed basin and is sheltered from the sea by an artificial breakwater leaving two openings, El-Boughaz and El-Silsila. Seven stations covering the area of the EH were selected and surface sediments were collected seasonally from spring to winter 2002. The near bottom temperature varied seasonally with a minimum value in winter and a maximum in summer. In contrast to the temperature values, dissolved oxygen exhibited maximum values in cold seasons. The seasonal average of the total organic carbon ranged from 0.48 ± 0.16 to 4.42 ± 2.46%, while the total organic nitrogen ranged from 0.07 ± 0.08 to 0.42 ± 0.38%. The total carbohydrate had minimum and maximum values of 273 µg g -1 and 6539 µg g -1 .The combined amino acids represented the dominant biochemical class of organic matter in the EH sediments with an average of 3665 ± 1911 µg g -1 . The total bacterial count ranged from 1.4 x 10 4 to 1.4 x 10 7 colony forming unit (CFU) g -1 sediment dry weight. Amylolytic bacterial group was recorded in almost all sites and seasons, while proteolytic bacteria were dominant in spring and autumn. The variation in the abundance of amylolytic and proteolytic bacterial groups was found to be parallel to the variation in soluble carbohydrates and free amino acids. High percentage of H 2 S-producing bacteria was reported during summer at some stations confirming the low oxygen content of the sediment at these sites. Agar-degrading bacteria were found only in warm seasons. The count of coliform bacteria in the EH sediments was very low (< 10 CFU g -1 ) during all monitored seasons indicating that the EH marine environment was almost free of domestic waste discharge during this period.

Environmental Characteristics of the Egyptian Mediterranean Coast

“…The results of amino acids in the investigated area is comparable with total amino acids of the Eastern Harbor that is varied widely between 1021 µg/g in winter and 11843 µg/g in spring (Gouda et al, 2006).…”

Análise De Abundância Bacteriana No Estudo Da Ecologia Microbiana De Sedimentos Marinhos

“…Considerando a escala micrométrica relevante à célula individual, na análise de comunidades bacterianas é mais adequado que as bactérias, como a infauna maior, seja medida por volume e não por massa de sedimento (Deming & Carpenter 2008). Apesar disso, muitos autores dimensionam parâmetros bacterianos por massa de sedimento (ZoBell & Morita 1959, Deming & Colwell 1982, Rowe & Deming 1985, Wit et al 1997, Danovaro et al 1998, Danovaro & Serresi 2000, Dixon & Turley 2000, Danovaro et al 2002a,b, Luna et al 2002, Lunau et al 2005, Gouda et al 2006, Raghukumar et al 2006. A análise deste parâmetro por massa de sedimento seco origina resultados com distribuição bacteriana variando amplamente de acordo com a profundidade de coleta.…”

“…Para análise de abundância utilizando-se métodos de cultivo a amostra de sedimento coletada deve ser processada logo após a coleta, no entanto pode-se realizar a preservação por curtos períodos de tempo, refrigerando-se a amostra (Gouda et al 2006). No processo de preservação das amostras para posterior determinação da abundância através da análise direta (por microscopia ou citometria em fluxo), o formol tem sido a substância mais utilizada (Jannasch & Jones 1959, Meyer-Reil et al 1978, Deming & Colwell 1982, 1985, Rowe & Deming 1985, Velji & Albright 1986a,b, Bott & Kaplan 1990, Parkes et al 1994, Epstein & Rossel 1995, Relexans et al 1996, Wit et al 1997, Danovaro et al 1998, 2002a, Schmidt et al 1998, Manini et al 2004, Duhamel & Jacquet 2006, Raghukumar et al 2006, Deming & Carpenter 2008.…”

Application Studies of Alkaline Protease from Marine Engyodontium Album BTMF S10 in Detergent Industry and in Silver Recovery from Used X-Ray Films

“…In laundry detergents, alkaline proteases have a specialized catalytic function in the hydrolysis of protein stains like blood, milk, human perspiration, etc. The protease is now used more frequently as a detergent ingredient since it can clean effectively in non-phosphate, environmentally friendly detergents (Mei and Jiang, 2005;Gouda, 2006). An earlier investigation into the substrate preferences of E. album protease revealed that casein and haemoglobin were the two substrates for which the enzyme had the highest affinity (Chellappan et al, 2011).…”