The effect of sewage water on some physiological activities of cyanobacteria was studied. Metal-tolerant cyanobacterium
(Nostoc linckia) and metal-sensitive (Nostoc ri6ularis) were grown at three levels of sewage water (25, 50 and 75%). The growth
rate showed significant stimulation in low and moderate levels (50% for N. linckia and 25% for N. ri6ularis). Not only the number
of cells was elevated but also, the time required to reach the exponential and the stationary phases was reduced. Also, low levels
of sewage water increased chl.a content, photosynthetic O2-evolution, respiration and protein content. Similarly, heterocyst
frequency as well as nitrogenase activity were increased in cyanobacteria grown at low and moderate levels (25 and 50% sewage).
On the other hand, the high level of waste (75%) reduced growth and metabolic activities of the two species. N. linckia
accumulated about 30-fold of Zn and ten-fold of Cd than those of growth medium (50% sewage water). Also, N. ri6ularis
accumulated about ten-fold of Zn and two-fold of Cd. The distribution of Cd and Zn in cells were investigated. About 65–60%
of Cd or Zn were found in pellets (sediment) as insoluble form in the two species. The soluble form (cytosolic fraction) after being
fractionated on sephadex G-(75-100) revealed two peaks with molecular weights of 70–75 and 40–45 kDa. These peaks were in
coincidence with Cd and Zn maxima. Nostoc ri6ulais showed more sensitivity to heavy metals than N. linckia, and accumulated
less amount of metal-binding proteins. Nostoc linckia seems to be tolerant to heavy metals (Zn and Cd) and is able to accumulate
this metal by adsorption on the pellets (cell surface) and:or through sequestration via metal-binding protein. Therefore it can be
recommended it to be employed in the purification of waste contaminated with these heavy metals. © 2000 Elsevier Science B.V.
All rights reserved.

Identification of common signals of nodulation control among legume species will facilitate progress in enhancing
symbiotic nitrogen fixation of legumes in sustainable agriculture system. Grafting experiments between soybean
and common bean were carried out to evaluate whether a common shoot signals control the expression of hypernodulation among the tow species. Grafting of a hypernodulating soybean mutant NOD1-3 shoots to three cultivars of normally nodulating common bean roots resulted in hypernodulation on roots of three tested cultivars of common bean. The shoot control of hypernodulation may be causally related to differential root isoflavonoid levels, which are also controlled by shoot factors. Isoflavonoid analysis from root extracts of grafted plants showed that NOD1-3 shoots had markedly higher root isoflavonoid concentrations in roots of both NOD1-3 and common bean cv. Adzuki compared with self-grafts of common bean Adzuki. Exogenous application of daidzein, genistein, coumestrol, glycitein and in combination at concentration of 10 µmol to the nutrient solution significantly increased
the nodule numbers of common bean cv. Adzuki. Therefore, the control of hypernodulation expression by isoflavonoid signal molecules translocated from shoot is common among legume species.

A rhizobial isolate was recovered from the root nodule of the faba bean (Vicia faba L.) grown in sludgecontaminated
fields in Upper Egypt. The isolate was identified as Rhizobium leguminosarum bv. viciae on
the bases of phenotypic characteristics and sequences of the gene encoding 16S rRNA. The isolate was
resistant to heavy metal stress in decreasing order Ba2þ (80 ppm), Zn2þ (70 ppm), Co2þ (50), Al3þ
(40 ppm), Ni2þ (30 ppm), and Cd2þ (10 ppm). The rhizobial isolate was used as an efficient biosorbent for
Cd2þ and Co2þ removal from aqueous solutions. The maximum adsorption capacities for Cd2þ and Co2þ
biosorption calculated from the Langmuir adsorption isotherm were 135.3 and 167.5 mg g1, respectively.
The adsorption isotherm for both heavy metals fit well with the Langmuir isotherm rather than the
Freundlich model with correlation coefficient (r2>0.98). This study indicates that the R. leguminosarum
bv. viciae isolate STDF-Egypt19 can be useful as an inexpensive and efficient bioremediation technology
to remove and recover heavy metal ions from an aqueous solution.

A rhizobial isolate was recovered from the root nodule of the faba bean (Vicia faba L.) grown in sludgecontaminated
fields in Upper Egypt. The isolate was identified as Rhizobium leguminosarum bv. viciae on
the bases of phenotypic characteristics and sequences of the gene encoding 16S rRNA. The isolate was
resistant to heavy metal stress in decreasing order Ba2þ (80 ppm), Zn2þ (70 ppm), Co2þ (50), Al3þ
(40 ppm), Ni2þ (30 ppm), and Cd2þ (10 ppm). The rhizobial isolate was used as an efficient biosorbent for
Cd2þ and Co2þ removal from aqueous solutions. The maximum adsorption capacities for Cd2þ and Co2þ
biosorption calculated from the Langmuir adsorption isotherm were 135.3 and 167.5 mg g1, respectively.
The adsorption isotherm for both heavy metals fit well with the Langmuir isotherm rather than the
Freundlich model with correlation coefficient (r2>0.98). This study indicates that the R. leguminosarum
bv. viciae isolate STDF-Egypt19 can be useful as an inexpensive and efficient bioremediation technology
to remove and recover heavy metal ions from an aqueous solution.

A rhizobial isolate was recovered from the root nodule of the faba bean (Vicia faba L.) grown in sludgecontaminated
fields in Upper Egypt. The isolate was identified as Rhizobium leguminosarum bv. viciae on
the bases of phenotypic characteristics and sequences of the gene encoding 16S rRNA. The isolate was
resistant to heavy metal stress in decreasing order Ba2þ (80 ppm), Zn2þ (70 ppm), Co2þ (50), Al3þ
(40 ppm), Ni2þ (30 ppm), and Cd2þ (10 ppm). The rhizobial isolate was used as an efficient biosorbent for
Cd2þ and Co2þ removal from aqueous solutions. The maximum adsorption capacities for Cd2þ and Co2þ
biosorption calculated from the Langmuir adsorption isotherm were 135.3 and 167.5 mg g1, respectively.
The adsorption isotherm for both heavy metals fit well with the Langmuir isotherm rather than the
Freundlich model with correlation coefficient (r2>0.98). This study indicates that the R. leguminosarum
bv. viciae isolate STDF-Egypt19 can be useful as an inexpensive and efficient bioremediation technology
to remove and recover heavy metal ions from an aqueous solution.

This study was devoted for H2 production from rotten fruits of date palm (Phoenix dactylifera
L.) by three fermentation stages. A facultative anaerobe, Escherichia coli EGY was used in
first stage to consume O2 and maintain strict anaerobic conditions for a second stage dark
fermentative H2 production by the strictly anaerobic Clostridium acetobutylicum ATCC 824.
Subsequently, a third stage photofermentation using Rhodobacter capsulatus DSM 1710 has
been conducted for the H2 production. The maximum total H2 yield of the three stages
(7.8 mol H2 mol
1 sucrose) was obtained when 5 g L
1 of sucrose was supplemented to
fermentor as rotten date fruits. A maximum estimated cumulative H2 yield of the three
stages (162 LH2 kg
1 fresh rotten dates) was estimated at the (5 g L
1) sucrose concentration.
These results suggest that rotten dates can be efficiently used for commercial H2
production. The described protocol did not require addition of a reducing agent or flashing
with argon which both are expensive.

This study was devoted for H2 production from rotten fruits of date palm (Phoenix dactylifera
L.) by three fermentation stages. A facultative anaerobe, Escherichia coli EGY was used in
first stage to consume O2 and maintain strict anaerobic conditions for a second stage dark
fermentative H2 production by the strictly anaerobic Clostridium acetobutylicum ATCC 824.
Subsequently, a third stage photofermentation using Rhodobacter capsulatus DSM 1710 has
been conducted for the H2 production. The maximum total H2 yield of the three stages
(7.8 mol H2 mol
1 sucrose) was obtained when 5 g L
1 of sucrose was supplemented to
fermentor as rotten date fruits. A maximum estimated cumulative H2 yield of the three
stages (162 LH2 kg
1 fresh rotten dates) was estimated at the (5 g L
1) sucrose concentration.
These results suggest that rotten dates can be efficiently used for commercial H2
production. The described protocol did not require addition of a reducing agent or flashing
with argon which both are expensive.

This study was devoted for H2 production from rotten fruits of date palm (Phoenix dactylifera
L.) by three fermentation stages. A facultative anaerobe, Escherichia coli EGY was used in
first stage to consume O2 and maintain strict anaerobic conditions for a second stage dark
fermentative H2 production by the strictly anaerobic Clostridium acetobutylicum ATCC 824.
Subsequently, a third stage photofermentation using Rhodobacter capsulatus DSM 1710 has
been conducted for the H2 production. The maximum total H2 yield of the three stages
(7.8 mol H2 mol
1 sucrose) was obtained when 5 g L
1 of sucrose was supplemented to
fermentor as rotten date fruits. A maximum estimated cumulative H2 yield of the three
stages (162 LH2 kg
1 fresh rotten dates) was estimated at the (5 g L
1) sucrose concentration.
These results suggest that rotten dates can be efficiently used for commercial H2
production. The described protocol did not require addition of a reducing agent or flashing
with argon which both are expensive.

The levels of GH, IGF-1, blood glucose and glycosylated plasma proteins (GPP) were determined in sera of diabetics (19 with and 18 without DR, 17 with IDDM and 20 with NIDDM). The levels of the four parameters were significantly higher in diabetics with and without retinopathy compared with controls. Patients with retinopathy had higher levels than those with nonproliferative changes. Serum GH and IGF-1 were higher in IDDM than in NIDDM. In patients with retinopathy, GH was correlated with the duration of diabetes and random blood glucose while IGF-1 did not correlate. It seems that increase GH and IGF-1 levels have possible contribution to the pathogenesis and progression of DR, especially in IDDM besides blood glucose and GPP excess. Such levels do appear to identify diabetics at high risk for rapid deterioration of vision and hence may be useful in selecting those for more intensive therapy.

The levels of GH, IGF-1, blood glucose and glycosylated plasma proteins (GPP) were determined in sera of diabetics (19 with and 18 without DR, 17 with IDDM and 20 with NIDDM). The levels of the four parameters were significantly higher in diabetics with and without retinopathy compared with controls. Patients with retinopathy had higher levels than those with nonproliferative changes. Serum GH and IGF-1 were higher in IDDM than in NIDDM. In patients with retinopathy, GH was correlated with the duration of diabetes and random blood glucose while IGF-1 did not correlate. It seems that increase GH and IGF-1 levels have possible contribution to the pathogenesis and progression of DR, especially in IDDM besides blood glucose and GPP excess. Such levels do appear to identify diabetics at high risk for rapid deterioration of vision and hence may be useful in selecting those for more intensive therapy.