Colony structure, population structure, and sharing of foraging trees in the ant Myrmecia nigriceps (Hymenoptera: Formicidae)

Foraging ants face many dangers in search of food and often need to defend their prey to ensure the colony’s survival, although ants may also follow a peaceful foraging strategy. A non-aggressive approach is seen in the Australian bull ant Myrmecia nigriceps, in that workers of neighboring nests sometimes share foraging trees. In this study, we observed 31 nests at Mount Majura Nature Reserve in Canberra (Australia), 12 of which shared a foraging tree with at least one other nest in at least one of three nights. We genotyped 360 individuals at five published microsatellite loci and further established a set of nine polymorphic loci for M. nigriceps. Our results revealed a significant correlation between tree sharing and geographical distance between nests. We found no correlation between internest relatedness and tree sharing, geographical distance between nests and internest relatedness, and intranest relatedness and tree sharing. We further investigated the colony structure of M. nigriceps. All colonies were monodomous; the number of queens per colony ranged from one to two, and the number of fathers from one to three. No instances of worker drifting were found in this study.

One tree, many colonies: colony structure, breeding system and colonization events of host trees in tunneling Melissotarsus ants

Ants exhibit a striking variety of lifestyles, including highly specialist or mutualist species. The minute blind workers of the African genus Melissotarsus chew tunnels in live trees to accommodate their obligate partner scale insects. Their modified legs are adapted for tunneling, but are unsuited for walking outside, confining these ants to their initial host tree. Here, we investigated whether this unique lifestyle results in complex patterns of genetic diversity at different scales, from the same tree to different populations. Using 19 microsatellite markers, we assessed their mating strategy and colony structure among and across populations in South Africa. We showed that only one queen reproduces within a colony, mated with up to three males. Yet, several inseminated dealate queens are present in colonies; one probably replaces the older queen as colonies age. The reproduction of a single queen per colony at a given time results in genetic differentiation between colonies, even those located on the same tree. Overall, we discussed how the slow process of colony digging under the bark and the lack of worker patrolling above the bark might result in reduced competition between colonies and allow several secluded colonies to cohabit in a cramped space on a tree.

Characteristics of the community-structure of A2O processes under different temperature conditions in plateau areas

Background: In this study, laboratory-scale A2O wastewater treatment was performed in Linzhi at an altitude of 3000 meters. Water temperatures were maintained at four operating conditions (25°C, 20°C, 15°C, and 10°C). Sludge in the aerobic tank was assessed by 16SrRNA sequencing and composition analysis. The Phylum, Class, Order, Family, Genus, and Species of the sludge were also confirmed.Results: The bacteria within the sludge showed significant differences at varying temperatures (P<0.05). A significant correlation between the bacteria numbers in anaerobic tanks and anoxic tanks also occurred. Indicators of community richness, community uniformity, community diversity and other areas showed differences. Significant differences in bacteria abundance were also observed and differed to those of previously reported superior community categories and proportions. T-tests were used to identify temperature-sensitive community at each level. Correlation analysis of environmental factors and colony structure further confirmed the association between temperature and colony structure (P<0.05). The removal rates of TP, TN, NH3-N, and COD were all affected by the sample community structure. The variety of colony structure include nitrifying bacteria, denitrifying bacteria, phosphorus accumulating bacteria and other bacterial differed, but their proportions were relatively low. Heatmaps were used to identify species sensitive to temperature, TP, TN, NH3-N, COD at the species level.Conclusions: Amongst the common dominant bacteria at the species level, Bacteroidetes_bacterium_OLB10 was significantly related to temperature. Other common dominant bacteria that were related to temperature metagenome_g__Gordonia, unclassified_f__Burkholderiaceae, uncultured_bacterium_g__norank_f__Saprospiraceae.

Isolasi dan Karakteristik Bakteri Pendegradasi Selulosa dari Limbah Pusat Industri Mebel Antang Makassar

<p>Antang Furniture Center in Makassar is one of the wood industries and is still traditionally. The wood processing produces waste containing cellulose that is difficult to degrade. This study aims to isolate and observe the characteristics of cellulose degrading bacteria. This research was conducted at the Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Hasanuddin University, Makassar from March 2019 to November 2019. The method used was an experimental laboratory consisting of <em>Carboxyl Methyl Cellulose</em> (CMC) media for bacterial selection and characterization including microscopic morphology with Gram staining and morphology macroscopic with colony structure. The results showed that cellulose degrading bacteria were characterized by the formation of clear zones formed on CMC media in petri dishes. Based on macroscopic and microscopic morphological characteristics, eleven types of cellulose degrading bacteria isolates were obtained. The isolates obtained can be a source of bacterial isolates for further application in wood waste or other wastes that contain of cellulose.</p>

Internal structure and photosynthetic performance of Nostoc sp. colonies in the high Arctic

The physiological performance of <em>Nostoc</em> sp. colonies in the high Arctic was investigated based on their structure and function. To investigate the internal colony structure, a method based on vertical stacking of individual light microscopy images was tested under the conditions at a polar field station. The physiological state of sun-exposed and shaded surfaces of the colonies was assessed using variable chlorophyll fluorescence imaging under two distinct low- and high-light conditions. The 3D image of the internal structure of the colonies revealed a high number of cells in the central part of the colony. Two peaks of maximum cell density were observed, probably caused by two overlapping colony lobes or subcolonies. Light was the driving factor of photosynthetic activity, and the colony structure played a role in the rate of response to incoming light. Fluorescence imaging revealed heterogeneity of the photosynthetic activity in the colonies, with the maximum photosynthetic activity at the colony edge due to better access to nutrients. The differences between exposed and shaded surfaces were not as pronounced as was expected, either due to good photoacclimation to a broad range of light conditions, light distribution through translucent extracellular matrixes, or integration of fluorescence signals throughout the colonies. The slightly better photosynthetic performance under high light conditions may indicate photoacclimation of <em>Nostoc</em> sp. to a broad range of light conditions encountered in the field.