Adsorption of turbid materials by the cyanobacterium <Emphasis Type="Italic">Phormidium parchydematicum</Emphasis>

The present study investigated the adsorption of turbid materials such as clays, by microalgae. Among six tested microalgae, including Chlorophyceae and Cyanophyceae, a cyanobacterium, Phormidium parchydematicum strain KCTC 10851BP, and unicellular alga, Chlorella vulgaris strain UTEX 265, showed a higher turbidity-removal efficiency (TRE) of 99% and 93%, respectively, for clay-containing water after 24 h, which was much higher than the 36% for the control. The TREs of all the treatments were >95% after 24 h, except for the treatment with a lower algal density and optical density (OD) = 0.1. Phormidium parchydematicum demonstrated a slightly higher TRE than a polyaluminum chloride coagulant (Al₁₃(OH)₂₈Cl₉SO₄) for a turbid field water. Scanning electron microscope (SEM) observations revealed a dense adsorption of clay particles to the surface of P. parchydematicum. Thus, it would appear that P. parchydematicum and C. vulgaris can be used for clay removal in turbid water by sedimentation through microalgae–clay flocculation.     

Cyanuric acid biodegradation by a mixed bacterial culture of <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis> and <Emphasis Type="Italic">Acinetobacter</Emphasis> sp. in a packed bed biofilm reactor

Cyanuric acid (1,3,5-triazine-2,4,6-triol [OOOT]) is a common biodegradation byproduct of triazinic herbicides, frequently accumulated in soils or water when supplementary carbon sources are absent. A binary bacterial culture able to degrade OOOT was selected through a continuous selection process accomplished in a chemostat fed with a mineral salt (MS) medium containing cyanuric acid as the sole carbon and nitrogen source. By sequence comparison of their 16S rDNA amplicons, bacterial strains were identified as Agrobacterium tumefaciens, and Acinetobacter sp. When the binary culture immobilized in a packed bed reactor (PBR) was fed with MS medium containing OOOT (50 mg L⁻¹), its removal efficiencies were about 95%; when it was fed with OOOT plus glucose (120 mg L⁻¹) as a supplementary carbon source, its removal efficiencies were closer to 100%. From sessile cells, attached to PBR porous support, or free cells present in the outflowing medium, DNA was extracted and used for Random Amplification of Polymorphic DNA analysis. Electrophoretic patterns obtained were compared to those of pure bacterial strains, a clear predominance of A. tumefaciens in PBR was observed. Although in continuous suspended cell culture, a stable binary community could be maintained, the attachment capability of A. tumefaciens represented a selective advantage over Acinetobacter sp. in the biofilm reactor, favoring its predominance in the porous stone support.     

<Emphasis Type="Italic">In situ</Emphasis> carbon supplementation in large-scale cultivations of <Emphasis Type="Italic">Spirulina platensis</Emphasis> in open raceway pond

The objective of this study was to estimate the CO₂ absorptivity provided by an in situ carbon supply system using a photosynthetic culture of the cyanobacterium Spirulina platensis in an open raceway pond. The effects of initial total carbon concentrations (ranging from 0 to 0.1 mol/L), suspension depths (ranging from 5 to 20 cm) and pH values (ranging from 8.9 to 11.0) on the CO₂ absorptivity were studied. The results indicated that CO₂ absorptivity was positively correlated with pH value, negatively correlated with total carbon concentration, and only negligibly affected by the suspension depth. The optimum total carbon concentration range and pH range were 0.03 ∼ 0.09 mol/L and 9.7 ∼ 10.0, respectively. An average CO₂ absorptivity of 86.16% and average CO₂ utilization efficiency of 79.18% were achieved using this in situ carbon-supply system in large-scale cultivation of Spirulina platensis, with an initial total carbon concentration of 0.06 mol/L and pH value of 9.8. Our results demonstrated that this system could obtain a favorable CO₂ utilization efficiency in outdoor, large-scale cultivation of Spirulina platensis in open raceway ponds.     

Water relations advantages for invasive <Emphasis Type="Italic">Rubus</Emphasis> <Emphasis Type="Italic">armeniacus</Emphasis> over two native ruderal congeners

Despite species in the Rubus fruticosus complex (wild blackberry) being among the most invasive plants globally in regions with large annual fluctuations in water availability, little is known about their water relations. We compared water relations of a prominent member of the complex, R. armeniacus (Himalayan blackberry), with species native to the Pacific Northwest of North America (PNW), R. spectabilis (salmonberry) and R. parviflorus (thimbleberry). In eight stands of each species located near Portland, Oregon, USA, we measured mid-day hydraulic resistance (R _plant), and daily time series of stomatal conductance (g _s), leaf water potential (Ψ_lf), and environmental conditions at four time periods spanning the 2007 growing season. Although all species maintained Ψ_lf above −0.5 MPa in spring, R. armeniacus maintained less negative Ψ_lf (≥−1.0 MPa) than the natives in summer, a factor attributable to advantages in both its root and shoot systems. R _plant of R. armeniacus was ≤0.1 MPa mmol⁻¹ m² s for the duration of the study, and approximately 25–50% of R _plant for the native species in summer. R. armeniacus had higher g _s compared to the native species throughout the spring and summer, with approximately twice their rates in summer. Our R _plant and g _s results show that R. armeniacus has access to more water during PNW summers than congeneric natives, allowing it to maintain high water-use, and potentially helping it achieve higher growth and reproductive rates. Water relations may therefore be a critical component of the competitive and invasive success of R. armeniacus and other R. fruticosus species worldwide.     

Direct gene transfer study and transgenic plant regeneration after electroporation into mesophyll protoplasts of <Emphasis Type="Italic">Pelargonium</Emphasis> <Emphasis Type="Italic">×</Emphasis> <Emphasis Type="Italic">hortorum</Emphasis>, ‘Panaché Sud’

Direct genetic transformation of mesophyll protoplasts was studied in Pelargonium × hortorum. Calcein and green-fluorescent protein (GFP) gene were used to set up the process. Electroporation (three electric pulses from a 33-μF capacitor in a 250-V cm⁻¹ electric field) was more efficient than PEG 6000 for membrane permeation, protoplast survival and cell division. Transient expression of GFP was detected in 33–36% of electroporated protoplasts after 2 days and further in colonies. A protoplast suspension conductivity of >1,500 μS cm⁻¹ allowed high colony formation and plant regeneration. Stable transformation was obtained using the plasmid FAJ3000 containing uidA and nptII genes. When selection (50 mg l⁻¹ kanamycin) was achieved 6 weeks after electroporation, regenerated shoots were able to grow and root on 100 mg l⁻¹ kanamycin. The maximum transformation efficiency was 4.5%, based on the number of colonies producing kanamycin-resistant rooted plants or 0.7% based on the number of cultured protoplasts. Polymerase chain reaction (PCR) analysis on in vitro micropropagated plants showed that 18 clones out of 20 contained the nptII gene, while the uidA gene was absent. These results were confirmed after PCR analyses of five glasshouse-acclimatized clones.     

Development of a real-time TaqMan assay to detect <Emphasis Type="Italic">mendocina</Emphasis> sublineage <Emphasis Type="Italic">Pseudomonas</Emphasis> species in contaminated metalworking fluids

A TaqMan quantitative real-time polymerase chain reaction (qPCR) assay was developed for the detection and enumeration of three Pseudomonas species belonging to the mendocina sublineage (P. oleovorans, P. pseudoalcaligenes, and P. oleovorans subsp. lubricantis) found in contaminated metalworking fluids (MWFs). These microbes are the primary colonizers and serve as indicator organisms of biodegradation of used MWFs. Molecular techniques such as qPCR are preferred for the detection of these microbes since they grow poorly on typical growth media such as R2A agar and Pseudomonas isolation agar (PIA). Traditional culturing techniques not only underestimate the actual distribution of these bacteria but are also time-consuming. The primer–probe pair developed from gyrase B (gyrB) sequences of the targeted bacteria was highly sensitive and specific for the three species. qPCR was performed with both whole cell and genomic DNA to confirm the specificity and sensitivity of the assay. The sensitivity of the assay was 10¹ colony forming units (CFU)/ml for whole cell and 13.7 fg with genomic DNA. The primer–probe pair was successful in determining concentrations from used MWF samples, indicating levels between 2.9 × 10³ and 3.9 × 10⁶ CFU/ml. In contrast, the total count of Pseudomonas sp. recovered on PIA was in the range of <1.0 × 10¹ to 1.4 × 10⁵ CFU/ml for the same samples. Based on these results from the qPCR assay, the designed TaqMan primer–probe pair can be efficiently used for rapid (within 2 h) determination of the distribution of these species of Pseudomonas in contaminated MWFs.     

<Emphasis Type="Italic">Grias angustipetala</Emphasis> and <Emphasis Type="Italic">G. ecuadorica</Emphasis>, two new species of Lecythidaceae from western Ecuador

Grias angustipetala and G. ecuadorica, two new species from the wet forests of western Ecuador are described. Grias angustipetala occurs in the Awá Indígenous Territory and Reserva Ecológica Cotacachi-Cayapas in the Esmeraldas and adjacent Carchi Provinces between 50–1800 m elevation. Grias ecuadorica is found in the Los Ríos and Bolívar Provinces between 70–600 m elevation. The new species are illustrated and their relationships with related species are discussed.     

<Emphasis Type="Italic">Fopius arisanus</Emphasis> oviposition in four <Emphasis Type="Italic">Anastrepha</Emphasis> fruit fly species of economic importance in Mexico

We studied the oviposition performance of Fopius arisanus (Sonan) (Hymenoptera: Braconidae) attacking eggs of four fruit flies of the genus Anastrepha Schiner (Diptera: Tephritidae) under laboratory conditions. The complete process of oviposition on an individual egg of Anastrepha ludens (Loew) lasts in average 85.4 ± 2.9 s, including a tremor (25.8 ± 1.03 s) observed in the middle of this process related to the egg’s descent. The average parasitism of A. ludens egg was 60.9 ± 7.5%, with only 1.2% of superparasitized eggs. During individual acts of oviposition, we noted that F. arisanus possesses a highly flexible ovipositor that curves easily as it searches for additional suitable eggs, which may be of particular benefit when a female finds large clutches of eggs. The individual oviposition of F. arisanus in host fruits attacked by Anastrepha spp. varies with the egg clutch size of each fruit fly species: A. serpentina laid the biggest egg clutches (21.3 ± 1.4), followed by A. ludens (14.2 ± 0.9), and A. striata (1.0 ± 0.0) (=A. obliqua). The time spent by F. arisanus in individual ovipositions was parallel to these findings, reinforcing the idea that F. arisanus attacks several eggs in each individual insertion of its ovipositor. Neither formal oviposition acts, nor adult emergences of F. arisanus were registered in A. obliqua. We discuss the potential of F. arisanus as natural enemy of fruit flies of the genus Anastrepha, and explore the eventual developing of its mass rearing. Handling Editor: Torsten Meiners.     

Ontogenetic shift in dietary preference and low dietary overlap in rohu (<Emphasis Type="Italic">Labeo rohita</Emphasis>) and common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis>) in semi-intensive polyculture ponds

In order to investigate ontogenetic changes in diet and diet overlap between rohu (Labeo rohita) and common carp (Cyprinus carpio) in polyculture ponds, food preferences of different size classes of these fishes were quantified. Rohu diet consisted of both phytoplankton and zooplankton, and there was a distinct ontogenetic shift in the relative importance of these food items. Zooplankton was the dominant food for rohu up to 20.6 cm total length (TL) and then gradually decreased in importance as fish grew. Phytoplankton was initially a minor component of rohu diet but gradually increased in importance and became the dominant food for rohu at 24.2 cm TL. Phytoplankton biovolume in rohu guts was positively correlated with fish size (TL). Chesson’s α indicated that rohu of all sizes preferentially selected Cladocera and avoided Cyanophyceae and Euglenophyceae. Young rohu initially preferred Rotifera and Copepoda but gradually switched to Bacillariophyceae and Chlorophyceae. Common carp diet consisted of phytoplankton, zooplankton, and benthic macroinvertebrates, but was dominated by benthic macroinvertebrates (63–92% of total diet). As common carp grew, the proportion of zooplankton ingested decreased and the proportion of benthic macroinvertebrates increased. Benthic macroinvertebrate biovolume in common carp guts was positively correlated with fish size. Common carp of up to 15.4 cm TL preferentially selected zooplankton, but common carp larger than 18.9 cm TL avoided this food item. Common carp of all sizes avoided phytoplankton. A low dietary overlap was found between rohu and common carp (Schoener overlap index: 0.08–0.35), probably due to ingestion of smaller quantities of zooplankton by the latter. Dietary overlap also decreased with increasing rohu and common carp size because of divergent ontogenetic shifts in dietary preferences of the two species.     

Activity-density of <Emphasis Type="Italic">Pardosa cribata</Emphasis> in Spanish citrus orchards and its predatory capacity on <Emphasis Type="Italic">Ceratitis capitata</Emphasis> and <Emphasis Type="Italic">Myzus persicae</Emphasis>

The wolf spider Pardosa cribata Simon is the most abundant ground-dwelling spider inhabiting citrus orchards in eastern Spain. However, little is known about its activity-density and its predatory role in the citrus agrosystem. Here we report on the activity-density of P. cribata monitored by pitfall traps, and on its capacity to prey on two citrus pests that appear both in the citrus canopy and the ground cover, Ceratitis capitata (Wiedemman) and Myzus persicae (Sulzer), respectively. Pardosa cribata was present in citrus orchards throughout the year, with a peak in spring and a higher peak in summer. Pardosa cribata preyed on adults and third-instar larvae but not on pupae of C. capitata. A type II functional response was obtained for teneral-like adults, with an estimated attack rate (a′) of 0.771 ± 0.213 days⁻¹ and a handling time (T _h) of 0.051 ± 0.013 days. Pardosa cribata also preyed efficiently on M. persicae, giving a type II functional response with an estimated attack rate and handling time of 2.833 ± 0.578 days⁻¹ and 0.031 ± 0.001 days, respectively. The data reported here indicate that this wolf spider could play an important role in regulating both these pests, and therefore might contribute to developing conservation biological control strategies for citrus pests. Handling Editor: Arne Jenssen.     

<Emphasis Type="Italic">In Silico</Emphasis> sequence analysis and molecular modeling of the three-dimensional structure of DAHP synthase from <Emphasis Type="Italic">Pseudomonas fragi</Emphasis>

The shikimate pathway is involved in production of aromatic amino acids in microorganisms and plants. The enzymes of this biosynthetic pathway are a potential target for the design of antimicrobial compounds and herbicides. 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase (DAHPS) catalyzes the first step of the pathway. The gene encoding DAHPS was cloned and sequenced from Pseudomonas fragi, the bacterium responsible for spoilage of milk, dairy products and meat. Amino acid sequence deduced from the nucleotide sequence revealed that P. fragi DAHPS (Pf-DAHPS) consists of 448 amino acids with calculated molecular weight of ∼50 kDa and isoelectric point of 5.81. Primary sequence analysis of Pf-DAHPS shows that it has more than 84% identity with DAHPS of other Pseudomonas species, 46% identity with Mycobacterium tuberculosis DAHPS (Mt-DAHPS), the type II DAHPS and less than 11% sequence identity with the type I DAHPS. The three-dimensional structure of Pf-DAHPS was predicted by homology modeling based on the crystal structure of Mt-DAHPS. Pf-DAHPS model contains a (β/α)₈ TIM barrel structure. Sequence alignment, phylogenetic analysis and 3D structure model classifies Pf-DAHPS as a type II DAHPS. Sequence analysis revealed the presence of DAHPS signature motif DxxHxN in Pf-DAHPS. Highly conserved sequence motif RxxxxxxKPRT(S/T) and xGxR present in type II DAHPS were also identified in Pf-DAHPS sequence. High sequence homology of DAHPS within Pseudomonas species points to the option of designing a broad spectrum drug for the genus. Pf-DAHPS 3D model provides molecular insights that may be beneficial in rationale inhibitor design for developing effective food preservative against P. fragi.     

Detecting <Emphasis Type="Italic">Suaeda salsa</Emphasis> L<Emphasis Type="Italic">.</Emphasis> chlorophyll fluorescence response to salinity stress by using hyperspectral reflectance

Measurements of chlorophyll fluorescence and hyperspectral reflectance were used to detect salinity stress in Suaeda salsa L., beach of Dongtai, Jiangsu Province, China. Three experimental sites were used in our study, which belong to low salinity, middle salinity and high salinity. The results showed that leaf chlorophyll fluorescence changed along salinity gradient. To select the sensitive hyperspectral ranges of leaf chlorophyll fluorescence, the correlationship between leaf chlorophyll fluorescence and hyperspectral reflectance was regressed and analyzed. Statistical results indicated that the 680 and 935 nm were the most sensitive hyperspectral bands for estimating leaf chlorophyll fluorescence. Then, 11 relative hyperspectral indices were selected based on the sensitive bands and previous literature. (R ₆₈₀ − R ₉₃₅)/(R ₆₈₀ + R ₉₃₅) and R ₆₈₀/R ₉₃₅ have higher correlationship coefficient (R) and lower root mean square error, may be used for detecting chlorophyll fluorescence, such as F _o, F _m, F _v/F _m, qP, and ΦPSII, while NPQ may be detected by (R ₇₈₀ − R ₇₁₀)/(R ₇₈₀ − R ₆₈₀). These results suggest that chlorophyll fluorescence of halophyte response to salinity stress could be identified by remote sensing.     

Statistical medium optimization and biodegradative capacity of <Emphasis Type="Italic">Ralstonia eutropha</Emphasis> toward <Emphasis Type="Italic">p</Emphasis>-nitrophenol

The effect of p-nitrophenol (PNP) concentration with or without glucose and yeast extract on the growth and biodegradative capacity of Ralstonia eutropha was examined. The chemical constituents of the culture medium were modeled using a response surface methodology. The experiments were performed according to the central composite design arrangement considering PNP, glucose and yeast extract as the selected variables whose influences on the degradation was evaluated (shaking in reciprocal mode, temperature of 30°C, pH 7 and test time of about 9 h). Quadratic polynomial regression equations were used to quantitatively explain variations between and within the models (responses: the biodegradation capacity and the biomass formation). The coefficient of determination was high (R _adjusted² = 0.9783), indicating the constructed polynomial model for PNP biodegradative capacity explains the variation between the regressors fairly well. A PNP removal efficiency of 74.5% occurred within 9 h (15 mg/L as the initial concentration of PNP with use of yeast extract at 0.5 g/L).     

Utilization of dibenzothiophene as sulfur source by <Emphasis Type="Italic">Microbacterium</Emphasis> sp. <Emphasis Type="Italic">NISOC-06</Emphasis>

Oil-polluted soils were sampled from National Iranian South Oil Company (NISOC) for isolation and screening of C–S and not C–C targeted Dibenzothiophene (DBT) degrading microorganisms. Microbacterium sp. NISOC-06, a C–S targeted DBT degrading bacterium, was selected and its desulfurization ability was studied in aqueous phase and water-gasoline biphasic systems. The 16srRNA gene was amplified using universal eubacteria-specific primers, PCR product was sequenced and the sequence of nearly 1,500 bp 16srDNA was studied. Based on Gas Chromatography results Microbacterium sp. NISOC-06 utilized 94.8% of 1 mM DBT during the 2 weeks of incubation. UV Spectrophotometry and biomass production measurements showed that the Microbacterium sp. NISOC-06 was not able to utilize DBT as a carbon source. There was no accumulation of phenolic compounds as Gibb’s assay showed. Biomass production in a biphasic system for which DBT-enriched gasoline was used as the sulfur source indicated the capability of Microbacterium sp. NISOC-06 to desulfurize gasoline.     

Enhanced production and characterization of a β-glucosidase from <Emphasis Type="Italic">Bacillus halodurans</Emphasis> expressed in <Emphasis Type="Italic">Escherichia coli</Emphasis>

A putative β-glucosidase gene from the genome of Bacillus halodurans C-125 was expressed in E. coli under the regulation of T7lac promoter. On induction with isopropyl-β-D-1-thiogalactopyranoside, the enzyme expressed at ∼40% of the cell protein producing 238 mg/liter culture. With increase in culture cell density to A ₆₀₀ 12 in auto-inducing M9NG medium, β-glucosidase production increased 3-fold. Approximately 70% of the expressed enzyme was in a soluble form, while the rest was in an insoluble fraction of the cell lysate. The soluble and active form of the expressed enzyme was purified by ammonium sulfate precipitation followed by ion-exchange chromatography to a purity >98%. The mass of the enzyme as determined by MALDI-TOF mass spectrometry was 51,601 Da, which is nearly the same as the calculated value. Phylogenetic analysis of the β-glucosidase of B. halodurans was found to cluster with members of the genus Bacillus. Temperature and pH optima of the enzyme were found to be 45°C and 8.0, respectively, under the assay conditions. K _m and k _cat against p-nitrophenyl-β-D-glucopyranoside were 4 mM and 0.75 sec⁻¹, respectively. To our knowledge, this is the first report of high-level expression and characterization of a β-glucosidase from B. halodurans.     

Discovery of <Emphasis Type="Italic">Ophiostoma tsotsi</Emphasis> on <Emphasis Type="Italic">Eucalyptus</Emphasis> wood chips in China

Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8S region, of the ribosomal DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time.     

Feeding Ecology of <Emphasis Type="Italic">Trachypithecus pileatus</Emphasis> in India

We observed a group of capped langurs for 12 mo in the Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. We recorded the time of feeding on different food plant species, food categories, and the feeding heights of monkeys in trees. Capped langurs spent 68% of their feeding time on leaves, 16% on flowers, and 16% on fruits. Feeding on leaves was consistently high (p < 0.01) during the year, with the highest feeding in May (85%) and the lowest in January (47%). The seasonal difference in feeding on leaves is significant (p < 0.05): it was higher in summer and during monsoon. The feeding time on flowers was maximal (35%) in March and that on fruits and seeds was minimal (38%) in January. Langurs ate 52 plant species throughout the year. The largest number of plants (6) were species of Moraceae, and langurs spent more feeding time (20%) on them alone. The number of plants eaten per month varied significantly (p < 0.05). Langurs ate Gmelina arborea, Albizzia lucida, Ficus glomereta, and Makania micrantha throughout the year. They spent 44% of their feeding time in terminal canopies and their average feeding height was 30–35 m. This is the first study to examine the feeding ecology of capped langurs and provides baseline data for the species.     

Hormonal control of the outgrowth of axillary buds in <Emphasis Type="Italic">Alstroemeria</Emphasis> cultured <Emphasis Type="Italic">in vitro</Emphasis>

We study apical dominance in Alstroemeria, a plant with an architecture very different from the model species used in research on apical dominance. The standard explant was a rhizome with a tip and two vertically growing shoots from which the larger part had been excised leaving ca. 1 cm stem. The axillary buds that resumed growth were located at this 1-cm stem just above the rhizome. They were released by removal of the rhizome tip and the shoot tips. Replacement of excised tips by lanolin with indole-3-butyric acid (IBA) restored apical dominance. The auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and N-1-napthylphthalamic acid (NPA) reduced apical dominance. 6-Benzylaminopurine (BAP) enhanced axillary bud outgrowth but the highest concentrations (> 9 μM) caused fasciation. Thidiazuron (TDZ) did not show improvement relative to BAP. Even though the architecture of Alstroemeria and the model species are very different, their hormonal mechanisms in apical dominance are for the greater part very similar.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of ten threatened species of <Emphasis Type="Italic">Mammillaria</Emphasis> (Cactaceae)

Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number. For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8 and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d.