Exogenously Treated Mammalian Sex Hormones Affect Inorganic Constituents of Plants

The present study was undertaken to reveal the changes in inorganic constituents of plants exposed to mammalian sex hormones (MSH). Chickpea leaves were sprayed with 10⁻⁴, 10⁻⁶, 10⁻⁹, 10⁻¹², and 10⁻¹⁵ M concentrations of progesterone, β-estradiol, and androsterone at 7th day after sowing. The plants were harvested at the end of 18 days after treatment of MSH solutions and the inorganic components determined using a wavelength-dispersive X-ray fluorescence spectroscopy technique. At all of the concentrations tested, MSH significantly increased the contents of K, S, Na, Ca, Mg, Zn, Fe, P, Cu, and Ni. Interestingly, only Mn and Cl contents decreased. The maximum changes in the inorganic composition were recorded at 10⁻⁶ M for plants treated with progesterone and 10⁻⁹ M for plants treated with β-estradiol and androsterone.     

Effects of Progesterone, β-Estradiol,and Androsterone on the Changes of Inorganic Element Content in Barley Leaves

The present study was performed to determine the changes in inorganic element content in barley leaves of mammalian sex hormones (MSH). Barley leaves were sprayed with 10⁻⁴, 10⁻⁶, 10⁻⁹, 10⁻¹², 10⁻¹⁵ M concentrations of progesterone, β-estradiol, and androsterone at 7th day after sowing. The plants were harvested at the end of 18 days after treatment with MSH solutions. The inorganic element concentrations were determined using wavelength dispersive X-ray fluorescence spectroscopy technique. Although the all MSH concentrations significantly (p < 0.05) increased the concentrations of calcium, magnesium, phosphorus, sulfur, copper, manganese, aluminum, zinc, iron, potassium, and chlorine, it decreased those of sodium concentration in barley leaves. The maximum changes in the element concentrations were obtained at 10⁻⁹ M for plant leaves treated with progesterone, 10⁻⁶ M for plant leaves treated with β-estradiol and androsterone. The present study elucidated that MSH significantly (p < 0.05) affected the inorganic element concentrations in barley leaves.     

Polyamines increase carpospore output and growth during in vitro cultivation of Hydropuntia cornea

Carpospore output and development in the marine red alga Hydropuntia cornea J. Agardh. were increased by adding polyamines (PAs) (putrescine, spermidine and spermine) singly or in combinations at 10⁻⁹, 10⁻⁶ and 10⁻³ M. Cell divisions after spore release and development of apical axis between 17 and 21 days characterized carpospore development. PAs increased carpospore development by promoting cell divisions to form cell masses between day 2 and 3. Morphogenesis to develop apical axes occurred at day 7. Spermine at 10⁻⁶ M and a combination of putrescine 10⁻⁹ M + spermidine 10⁻⁹ M + spermine 10⁻⁹ M gave a higher number of carpospores and enhanced their further development to sporelings.     

Effect of amplification ofdhfr andlac Z genes on growth and β-galactosidase expression in suspension cultures of recombinant CHO cells

Studies were conducted to characterize the effect of gene amplification and foreign gene expression on recombinant CHO cell growth. Chinese hamster ovary (CHO) cells were transfected with an expression vector containing the gene for dihydrofolate reductase (dhfr) and the gene for human β-interferon (β-IFN) or thelac Z gene which codes for β-galactosidase (β-gal). The recombinant genes in these CHO cells were amplified stepwise by growth in 0, 10⁻⁷, and 10⁻⁶ M methotrexate (MTX), and the β-gal expressing cells were adapted to suspension culture. Flow cytometric methods (FCM) were used to measure the distribution of amplifieddhfr gene content and foreign β-gal gene expression in the cell populations. A biochemical assay for β-gal was also used. Beta-gal expression was found to increase with increasing gene amplification. The growth rate of recombinant CHO cells at 10⁻⁷ M MTX was found to be 20% lower than that of recombinant CHO cells in MTX-free medium, and the cell growth rate at 10⁻⁶ M MTX was 20% lower than that of recombinant CHO cells at 10⁻⁷ M MTX. There was no effect of 10⁻⁵ M MTX on the growth of CHO-DG44 (dhfr-) cells. The reduction of growth rate in recombinant CHO cells is therefore thought to be mainly due to the effect ofdhfr and foreign gene amplification and increased β-galactosidase expression.     

Effects of arsenate on the growth and microcystin production of Microcystis aeruginosa isolated from Taiwan as influenced by extracellular phosphate

Arsenic pollution and eutrophication are both prominent issues in the aquaculture ponds of Taiwan. It is important to study the effects of arsenic on algal growth and toxin production in order to assess the ecological risk of arsenic pollution, or at least to understand naturally occurring ponds. The sensitivity of algae to arsenate has often been linked to the structural similarities between arsenate and phosphate. Thus, in this study we examined the effects of arsenate (10⁻⁸ to 10⁻⁴ M) on Microcystis aeruginosa TY-1 isolated from Taiwan, under two phosphate regimes. The present study showed that M. aeruginosa TY-1 was arsenate tolerant up to 10⁻⁴ M, and that this tolerance was not affected by extracellular phosphate. However, it seems that extracellular phosphate contributed to microcystin production and leakage by M. aeruginosa in response to arsenate. Under normal phosphate conditions, total toxin yields after arsenate treatment followed a typical inverted U-shape hormesis, with a peak value of 2.25 ± 0.06 mg L⁻¹ in the presence of 10⁻⁷ M arsenate, whereas 10⁻⁸ to 10⁻⁶ M arsenate increased leakage of ∼75% microcystin. Under phosphate starvation, total toxin yields were not affected by arsenate, while 10⁻⁶ and 10⁻⁵ M arsenate stimulated microcystin leakage. It is suggested that arsenate may play a role in the process of microcystin biosynthesis and excretion. Given the arsenic concentrations in aquaculture ponds in Taiwan, arsenate favors survival of toxic M. aeruginosa in such ponds, and arsenate-stimulated microcystin production and leakage may have an impact on the food chain.     

Mammalian sex hormones stimulate antioxidant system and enhance growth of chickpea plants

In the present study, it was aimed to investigate the influence of exogenous mammalian sex hormones (MSH) (progesterone, β-estradiol and androsterone) on the morphological (root and shoot growth) and biochemical parameters (protein and sugar content, antioxidant enzyme activities, and lipid peroxidation and H₂O₂ levels) of chickpea (Cicer arietinum L.) plants growing under control conditions. The solutions of hormones prepared at different concentrations (10⁻⁴, 10⁻⁶, 10⁻⁹, 10⁻¹² and 10⁻¹⁵ M) were sprayed once on the leaves of 7-day plants. The plants were harvested on 18 days after the hormone treatment. Although all of the hormones at the tested concentrations significantly increased plant growth, soluble protein and sugar contents, and antioxidant enzyme activities [superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT)], they decreased H₂O₂ content and lipid peroxidation level when compared with control plants. The activities of SOD, POX and CAT reached to the highest levels at 10⁻⁶ M for progesterone, and 10⁻⁹ M for β-estradiol and androsterone, which maximum growth, protein and sugar contents were determined. The same concentrations also resulted in the lowest levels for H₂O₂ content and lipid peroxidation. It can be interpreted that the MSH improve plant growth and development by affecting some biochemical parameters including antioxidative system.     

Environmentally relevant cadmium concentrations affect development and induce apoptosis of <Emphasis Type="Italic">Paracentrotus lividus</Emphasis> larvae cultured in vitro

Sea urchin embryos and larvae represent suitable model systems on where to investigate the effects of heavy metals on development and cell viability. Here, we tested the toxic effects of low (10⁻¹² M), medium (10⁻⁹ M), and high (10⁻⁶ M) cadmium chloride concentrations, mimicking unpolluted, moderately and highly polluted seawaters, respectively, on Paracentrotus lividus sea urchins offspring. Larvae were continuously treated from fertilization and inspected at time intervals comprised between 10 and 30 days of development. Delays and/or morphological abnormalities were firstly evident in larvae treated for 15 days with high cadmium (10⁻⁶ M) and for 25 days with medium cadmium (10⁻⁹ M). Major defects consisted in the reduction and lack of arms and skeleton elongation. No obvious differences with respect to controls were observed in embryos/larvae exposed to low cadmium (10⁻¹² M), even after 30 days of exposure. Using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL) assay on larvae whole mounts, we detected apoptosis after 10 days of treatment with 10⁻⁶ and 10⁻⁹ M CdCl_2, when no morphological abnormalities were recognizable yet. Supernumerary apoptotic cells were found in arm buds, ciliary bands, and apex. In conclusion, echinoderm embryos and larvae represent candidates of choice for the study of stress and defense mechanisms activated by cadmium exposure.     

Acetylcholine prevents angiotensin II-induced oxidative stress and apoptosis in H9c2 cells

Apoptosis of cardiomyocytes plays an important role in the development of cardiovascular diseases (CVD). Numerous studies have shown that generation of reactive oxygen species (ROS) induced by the renin-angiotensin system (RAS) is involved in this pathological process. Recent studies also suggested that acetylcholine (ACh) prevented the hypoxia-induced apoptosis of mouse ES cells by inhibiting the ROS production. However, whether ACh can inhibit the action of angiotensin II (Ang II) and subsequently prevent CVD development remains unclear. In this study, H9c2 cells were stimulated by 10⁻⁶ M Ang II for 24 h with or without 10⁻⁵ M ACh, 10⁻⁵ M ACh + 10⁻⁴ M atropine respectively. The results demonstrated that Ang II increased apoptosis index by fourfold (vs. the control group, P < 0.01), which were significantly diminished by ACh. However, the atropine (ACh receptor [AChR] inhibitor) treatment blocked the protective effect of ACh. Subsequently, Ang II significantly increases the expression and activity of NADPH oxidase so that ROS production is increased by sevenfold (vs. control group, P < 0.01). The activity and expression of caspase-3 along with the Bax/Bcl2 ratio and the levels of p38 mitogen activated protein kinase (MAPK) phosphorylation also appeared to follow a similar trend. Furthermore, we observed that ACh could reduce up-regulation of AT1 receptor expression induced by Ang II. However, all these effects of ACh were inhibited by atropine. In conclusion, ACh prevents Ang II-induced H9c2 cells apoptosis through down-regulation of the AT1 receptor and inhibition of ROS-mediated p38 MAPK activation as well as regulation of Bcl-2, Bax and caspase-3.     

High stilbenes accumulation in root cultures of <Emphasis Type="Italic">Cayratia trifolia</Emphasis> (L.) Domin grown in shake flasks

The Root cultures of Cayratia trifolia (Vitaceae) a tropical lianas, were maintained in liquid Murashige and Skoog’s medium containing 0.5 mg l⁻¹ NAA, 0.1 mg l⁻¹ kinetin with 3% sucrose. These root cultures when grown with 6% sucrose accumulated stilbenes (piceid, resveratrol, viniferin, ampelopsin) in high amounts, which on elicitation by 500 mg l⁻¹ yeast extract, 50 μM salicylic acid (SA), 50 μM methyl jasmonate (MeJa), 500 μM ethrel added at 25th day, increased up to ninefolds (7.1 mg l⁻¹). Addition of alar or phenylalanine along with the elicitors further enhanced the stilbenes content. In the present study, stilbenes accumulation up to 12 folds (9.2 mg l⁻¹) was obtained with SA and alar. The SA was the most effective in increasing the stilbenes contents while less than control values were recorded in the cells treated with MeJa. The roots could be grown up to 2 l flasks. The present work demonstrates that presence of precursor and sucrose during elicitation at an appropriate time combined with growth retardation significantly increased the production of stilbenes in C. trifolia cell cultures.     

The effect of <Emphasis Type="Italic">Poterioochromonas</Emphasis> abundance on production of intra- and extracellular microcystin-LR concentration

Due to its capability for producing various microcystins, Microcystis aeruginosa is recognized as one of the most toxic, bloom-forming cyanobacteria. In this study, the fates of intra- and extracellular microcystin-LR (MC-LR) were investigated when the mixotrophic golden alga Poterioochromonas sp. (ZX1) was grazing on M. aeruginosa cells. In the control groups, the total MC-LR concentration increased with the growth of M. aeruginosa with an MC-LR content per cell of 0.5–1.5 × 10⁻⁸ μg cell⁻¹. In the treatment with ZX1, the total MC-LR decreased linearly throughout the incubation period. In particular, intracellular MC-LR disappeared with a loss of M. aeruginosa cells in the first few days. Part of the intracellular MC-LR was released to the medium under the grazing stress, resulting in an increase of extracellular MC-LR. The degradation rate of MC-LR was positively related to the initial abundance of ZX1 and negatively related to that of M. aeruginosa. The inhibition ratio of MC-LR production dropped sharply from 98 to 67% when the initial abundance of M. aeruginosa increased from 10⁶ to 10⁷ cells ml⁻¹. However, it increased from 84 to 99% when the initial ZX1 abundance increased from 10⁴ to 10⁵ cells ml⁻¹. The effective removal of both M. aeruginosa cells and MC-LR was observed under lower M. aeruginosa abundance (<10⁶ cells ml⁻¹) and higher ZX1 abundance (>1% of M. aeruginosa abundance). Light had little impact on MC-LR degradation, but MC-LR degradation decreased due to the loss of ZX1 after 10 days of darkness. This study showed that the interactions between M. aeruginosa and ZX1 were strongly influenced by their initial abundances.     

Bioelectrical activity in the heart of the lugworm Arenicola marina

Standard microelectrode technique was used to study electrical activity of the isolated heart of the polychaete annelid, Arenicola marina. Typical pacemaker activity with slow diastolic depolarization was observed in all recordings. The average maximum diastolic potential (−58.4 ± 3.2 mV), the average amplitude of the action potential (28.7 ± 4.7 mV) and the average total duration of the action potential (2,434 ± 430 ms) were determined. There has been no gradient of automaticity observed in our studies, which suggests that all regions of the Arenicola heart could possess pacemaker functions. Acetylcholine (ACh) produced a concentration dependent (5 × 10⁻⁸–5 × 10⁻⁵ M) increase of the beating rate via increase in the rate of the diastolic depolarization. ACh (5 × 10⁻⁵ M) increased beating rate by 2.5-fold compared to the control rate. A stronger action of ACh resulted in depolarization, block of action potential generation and contracture of the heart. The non-hydrolysable ACh analog carbacholine (10⁻⁸–10⁻⁶ M) produced similar effects. All effects of ACh and carbacholine were abolished by 5 × 10⁻⁶ M atropine. d-Tubocurarine (5 × 10⁻⁵ M) did not significantly alter effects of ACh or carbacholine. Epinephrine (10⁻⁸–10⁻⁶ M) caused the slowing of pacemaker activity and marked decrease of action potential duration. 10⁻⁶ M epinephrine produced complete cardiac arrest. The effects of epinephrine were not significantly altered by the β-blocker propranolol (5 × 10⁻⁶ M). The β-agonist isoproterenol (10⁻⁷–10⁻⁵ M) and the α-agonist xylometazoline (10⁻⁶–10⁻⁵ M) did not produce significant effects. Thus, cholinergic effects in the Arenicola heart are likely to be mediated via muscarinic receptors, while the nature of adrenergic effects needs further investigation.     

Understanding the effect of organic pollutant fluoranthene on pea in vitro using cytokinins,ethylene, ethane and carbon dioxide as indicators

Environmental contaminants like polycyclic aromatic hydrocarbons can influence many biochemical and physiological processes in plants. The effect of 0.1, 1 and 5 mg l⁻¹ of fluoranthene (FLT) in combination with indole-3-acetic acid (IAA, 0.1 mg l⁻¹) or a combination of IAA and N⁶-benzyladenine (BA, both 0.1 mg l⁻¹) on the growth and production of ethylene, ethane and CO₂ in Pisum sativum L. cultivated for 21 days in vitro was investigated. In 21 days old plants also net photosynthesis rate, content of FLT and cytokinins were evaluated. FLT 5 mg l⁻¹ significantly inhibited the growth of pea after 21 days in both IAA and IAA + BA treatments, increased production of ethylene (by 11% in IAA and 14% in IAA + BA treatments, respectively) and ethane (by 28 and 18%) and decreased production of CO₂ (by 23 and 29%). The net photosynthesis rate decreased in response to FLT concentration by up to 51% under saturating irradiation (600–1,200 μmol m⁻² s⁻¹), as found in IAA + BA + FLT 5 mg l⁻¹ treatment. The content of FLT in pea plant shoots well correlated with increasing FLT treatment in both IAA and IAA + BA medium. The content of cytokinins in pea shoots changed in response to FLT treatment. FLT 5 mg l⁻¹ caused a rise in level of trans-zeatin (by 16% in IAA and 9% in IAA + BA treatments, respectively), dihydrozeatin riboside (by 27 and 50%), benzyladenine (by 3 and 80%), benzyladenine riboside (by 44 and 17%) and meta-topolin riboside (by 139 and 214%), no change in isopentenyladenine level and a decrease in meta-topolin level (by 33% in IAA and 36% in IAA + BA treatments, respectively). Cultivation of plants in vitro allowed not only to assess their growth, photosynthetic activity and the level of cytokinins, but also to extend the knowledge about the effect of PAHs on production of gaseous stress indicators like ethylene, ethane and CO₂. Recorded changes in all studied parameters show, that persistent organic pollutants like PAHs can negatively influence plant growth and development.     

Influence of growth regulators and elicitors on cell growth and α-tocopherol and pigment productions in cell cultures of <Emphasis Type="Italic">Carthamus tinctorius</Emphasis> L.

The present study examined the effects of plant growth hormones, incubation period, biotic (Trametes versicolor, Mucor sp., Penicillium notatum, Rhizopus stolonifer, and Fusarium oxysporum) and abiotic (NaCl, MgSO₄, FeSO₄, ZnSO₄, and FeCl₃) elicitors on cell growth and α-tocopherol and pigment (red and yellow) productions in Carthamus tinctorius cell cultures. The cell growth and α-tocopherol and pigment contents improved significantly on Murashige and Skoog (MS) liquid medium containing 50.0 μM α-naphthalene acetic acid (NAA) and 2.5 μM 6-Benzyladenine (BA) at 28 days of incubation period. Incorporation of T. versicolor (50 mg l⁻¹) significantly enhanced the production of α-tocopherol (12.7-fold) and red pigment (4.24-fold). Similarly, supplementation of 30 mg l⁻¹ T. versicolor (7.54-fold) and 70 mg l⁻¹ Mucor sp. (7.40-fold) significantly increased the production of yellow pigment. Among abiotic elicitors, NaCl (50–70 mg l⁻¹) and MgSO₄ (10–30 mg l⁻¹) significantly improved production of α-tocopherol (1.24-fold) and red pigment (20-fold), whereas yellow pigment content increased considerably by all the abiotic elicitor treatments. Taken together, the present study reports improved productions of α-tocopherol and the pigment as a stress response of safflower cell cultures exposed to these elicitors.     

Hyperosmolarity enhances transient recombinant protein yield in Chinese hamster ovary cells

The effect of hyperosmolarity on transient recombinant protein production in Chinese hamster ovary (CHO) cells was investigated. Addition of 90 mM NaCl to the production medium ProCHO5 increased the volumetric yield of recombinant antibody up to 4-fold relative to transfection in ProCHO5 alone. Volumetric yields up to 50 mg l⁻¹ were achieved in a 6 day batch culture of 3 l. In addition, hyperosmolarity reduced cell growth and increased cell size. The addition of salt to cultures of transiently transfected CHO cells is a simple and cost-effective method to increase TGE yields in this host.     

Relationship between tissue plasminogen activator production and specific growth rate in Chinese Hamster Ovary cells cultured in mannose at low temperature

Chinese hamster ovary (CHO) cells, producing human recombinant tissue plasminogen activator (tPA), were grown with mannose (5, 20 and 40 mM) instead of glucose at 31, 33 and 37°C. The highest tPA concentration (1.5 mg l⁻¹ at 144 h of cultivation) and tPA specific production rate (47 ng 10⁻⁶ cell h⁻¹) were obtained at 31°C and 40 mM mannose. Regardless of the temperature or mannose concentration used, an inverse relationship between the specific growth rate and tPA specific production rate was observed, suggesting that tPA production rate would be directly controlled by the growth rate.     

Medium Selection and Effect of Higher Oxygen Concentration Pulses on <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> var<Emphasis Type="Italic">. lepidiotum</Emphasis> Conidial Production and Quality

Rice and oat flours were analyzed as media for the production of conidia by M. anisopliae var. lepidiotum. The presence of peptone increased conidia yield regardless of the substrate used; however, the highest yield was achieved on oat flour media. The effect of oxygen on conidia production using oat-peptone medium was also studied at two levels: Normal atmosphere (21% O₂) and Oxygen-rich pulses (26% O₂). Maximum conidia production (4.25 × 10⁷ conidia cm⁻²) was achieved using 26% O₂ pulses after 156 h of culture, which was higher than 100% relative to conidial levels under normal atmosphere. Conidia yield per gram of biomass was 2.6 times higher with 26% O₂ (1.12 × 10⁷ conidia mg⁻¹). Conidia quality parameters, such as germination and hydrophobicity, did not show significant differences (P < 0.05) between those treatments. Bioassays parameters, using Tenebrio molitor adults, were analyzed for conidia obtained in both atmospheres and data were fitted to an exponential model. The specific mortality rates were 2.22 and 1.26 days⁻¹, whereas lethal times for 50% mortality were 3.90 and 4.31 days, for 26% O₂ pulses and 21% O₂ atmosphere, respectively. These results are relevant for production processes since an oxygen increase allowed superior levels of conidia by M. anisopliae without altering quality parameters and virulence toward Tenebrio molitor adults.     

Stimulation of menthol production in <Emphasis Type="Italic">Mentha piperita</Emphasis> cell culture

Plant cell culture provides an alternative means for producing secondary metabolites. In this study, experiments were carried out to study the impact of several parameters, independently and in combination, on the stimulation of menthol production in the cell suspension culture of Mentha piperita. Callus was obtained from leaf segments of in vitro grown plantlets on Murashige and Skoog (MS) medium supplemented with 0.2 mg l⁻¹of 2,4-dichlorophenoxy acetic acid to initiate cell suspension culture. This culture was maintained in half-strength MS medium supplemented with 0.2 mg l⁻¹of 2,4-dichlorophenoxy acetic acid at 15 d interval and used for further studies. Precursor feeding alone, i.e., menthone, at 35 μM concentration showed slightly improved productivity. γ-Cyclodextrin alone at 60 μM concentration and in combination with menthone feeding at 35 μM increased menthol yield up to 92 and 110 mg l⁻¹ in comparison to 77 mg l⁻¹ of control culture. Synergistic potentiation effect of menthone feeding at 35 μM and γ-cyclodextrin at 60 μM treatment followed by in situ adsorption with RP-8 also showed potential stimulation of menthol production in M. piperita cell culture. Fungal elicitor treatment showed enhanced production level up to 140.8 mg l⁻¹ in comparison to that of control. Further studies were carried out with the establishment of Agrobacterium tumefaciens (Ach5) gall-mediated calli, and consequently, cell suspension culture and results showed the significant enhancement of menthol yield up to 278 mg l⁻¹. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Carob pulp as raw material for production of the biocontrol agent <Emphasis Type="Italic">P. agglomerans</Emphasis> PBC-1

Large-scale production has been the major obstacle to the success of many biopesticides. The spreading of microbial biocontrol agents against postharvest disease, as a safe and environmentally friendly alternative to synthetic fungicides, is quite dependent on their industrial mass production from low-cost raw materials. Considerable interest has been shown in using agricultural waste products and by-products from food industry as nitrogen and carbon sources. In this work, carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1. Optimal sugar extraction was achieved at a solid/liquid ratio of 1:10 (w/v), at 25°C, for 1 h. Batch experiments were performed in shake flasks, at different concentrations and in stirred reactors at two initial inoculums concentrations, 10⁶ and 10⁷ cfu ml⁻¹. The initial sugar concentration of 5 g l⁻¹ allowed rapid growth (0.16 h⁻¹) and high biomass productivity (0.28 g l⁻¹ h⁻¹) and was chosen as the value for use in stirred reactor experiments. After 22 and 32 h of fermentation the viable population reached was 3.2 × 10⁹ and 6.2 × 10⁹ cfu ml⁻¹ in the fermenter inoculated at 10⁶ cfu ml⁻¹ and 2.7 × 10⁹ and 6.7 × 10⁹ cfu ml⁻¹ in the bioreactor inoculated at 10⁷ cfu ml⁻¹. A 78% reduction of the pathogen incidence was achieved with PBC-1 at 1 × 10⁸ cfu ml⁻¹, grown in medium with carob extracts, on artificially wounded apples stored after 7 days at 25°C against P. expansum.     

Effect of sucrose,light, and carbon dioxide on plantain micropropagation in temporary immersion bioreactors

In vitro physiology and carbon metabolism can be affected by the sink–source relationship. The effect of different sucrose concentrations (10, 30, and 50 g L⁻¹), light intensities (80 and 150 μmol m⁻² s⁻¹), and CO₂ levels (375 and 1,200 μmol mol⁻¹) were tested during plantain micropropagation in temporary immersion bioreactors. Activities of pyruvate kinase, phosphoenol pyruvate carboxylase, and the photosynthesis rate were recorded. From the morphological and practical point of view, the best results were obtained when plants were cultured with 30 g L⁻¹ sucrose, 80 μmol m⁻² s⁻¹ light intensity, and 1,200 μmol mol⁻¹ CO₂ concentration. This treatment improved leaf and root development, reduced respiration during in vitro culture, and increased starch level at the end of the hardening phase. In addition to that, the number of competent plants was increased from 80.0% to 91.0% at the end of the in vitro phase and the survival percentage from 95.71% to 99.80% during ex vitro hardening.     

Decolorization of Acid red 151 by Aspergillus niger SA1 under different physicochemical conditions

The fungal strain A. niger SA1 isolated from textile wastewater pond proved to be an important source of remediation (decolorization/degradation) for textile dye, AR 151 (Reactive diazo dye) under different physicochemical conditions. Decolorization assays of AR 151 were carried out in Simulated textile effluent under shake flask condition for 8 days. Decolorization (at 20 mg l⁻¹ of dye) and related biomass production overall decreased with increase in pH from 5 to 9, at 30°C. It was maximum (95.71%) at pH 5 with highest amount of three residual products (36.91 (α-naphthol = 5.72) (sulfanilic acid = 24.81) (aniline = 6.38)) besides 2.05 mg ml⁻¹ of biomass production at an optimum concentration 6 and 0.1 mg l⁻¹ of glucose and urea respectively. The formation of the three products followed a quite different pattern at different pH values, however, it was considerably low (Total = 2.81 mg l⁻¹) compared to the amount of decolorization (67.26%) at pH 8. Decolorization (95–97%) was most favored under mesophilic temperature (25–45°C). It increased i.e., 90–98% with subsequent increase in dye from 10 to 100 mg l⁻¹, kept ≥50% below 400 mg l⁻¹ and drastically declined to 17% at 500 mg l⁻¹ of dye. Apparently, decolorization is found to be associated with fungal growth and hyphal uptake mechanism (Biosorption/Bioadsorption), however, mineralization of AR 151 and related products under different operational conditions also suggested a metabolically mediated decolorization/degradation.