Changes in nutritional composition from bee pollen to pollen patty used in bumblebee rearing

Pollen patties are generally supplied to augment the nourishment of honey bee or bumblebee colonies during late winter or early spring. In the present study, we examined nutrient content of bee collected pollen (BP) and pollen patties (PT) prepared from those bee collected pollens in order to understand the chemical compositional change of pollen to pollen patty and figure out the possible benefits for bee’s health. Protein and fat contents of pollen patties were found lower than that reported for the respective bee pollens. Amino and fatty acids followed the same trend for the simple logical reason. In contrast, carbohydrate contents of pollen patties were found much higher than the bee pollen. The addition of sugar solution in the process of pollen patty preparation could presumably explain the change. Another possible determinant factor of bee’s preference of feed protein to fat ratio was found the highest for PT 2 (5.5) followed by PT 1 and BP 2 (4.1), BP Ref. (2.9) and the least value obtained for BP 1 (2.2). Additionally, we discuss the possible health benefits if the bee collected pollen is used as a human food supplement.     

Hive‐stored pollen of honey bees: many lines of evidence are consistent with pollen preservation,not nutrient conversion

Honey bee hives are filled with stored pollen, honey, plant resins and wax, all antimicrobial to differing degrees. Stored pollen is the nutritionally rich currency used for colony growth and consists of 40–50% simple sugars. Many studies speculate that prior to consumption by bees, stored pollen undergoes long‐term nutrient conversion, becoming more nutritious ‘bee bread’ as microbes predigest the pollen. We quantified both structural and functional aspects associated with this hypothesis using behavioural assays, bacterial plate counts, microscopy and 454 amplicon sequencing of the 16S rRNA gene from both newly collected and hive‐stored pollen. We found that bees preferentially consume fresh pollen stored for <3 days. Newly collected pollen contained few bacteria, values which decreased significantly as pollen were stored >96 h. The estimated microbe to pollen grain surface area ratio was 1:1 000 000 indicating a negligible effect of microbial metabolism on hive‐stored pollen. Consistent with these findings, hive‐stored pollen grains did not appear compromised according to microscopy. Based on year round 454 amplicon sequencing, bacterial communities of newly collected and hive‐stored pollen did not differ, indicating the lack of an emergent microbial community co‐evolved to digest stored pollen. In accord with previous culturing and 16S cloning, acid resistant and osmotolerant bacteria like Lactobacillus kunkeei were found in greatest abundance in stored pollen, consistent with the harsh character of this microenvironment. We conclude that stored pollen is not evolved for microbially mediated nutrient conversion, but is a preservative environment due primarily to added honey, nectar, bee secretions and properties of pollen itself.     

Nutritional effects of supplementary diets on brood development,biological activities and honey production of Apis mellifera L

The present research work was conducted to assess the impact of nutrient-enriched diet on the physiological activities and subsequently honey yield. Eighteen colonies of Apis mellifera L. were selected from Dera Ismail Khan region, KPK, Pakistan, during the winter and summer seasons, 2019–2020. Five pollen supplement diets were prepared and provided to screen out the palatable one to be fed as pollen alternative nutrition to bee bread. Results of diet consumption regarding mean data for consumption rate displayed that soybean flour enriched artificial diet was maximally consumed (74.34 g) by honey bees per week. Minimum consumption was observed for grinded groundnut enriched diet (64.62 g) which was relatively lesser than the other tested artificial diets. Results of area of worker brood disclosed that soybean flour fortified diet (1489.27 cm²/colony) statistically noteworthy than the other artificial diets whereas control (463.51 cm²/colony) was least effective. Highest bee strength (10.00 bee frames/colony) was noted in the bee colonies fed with soybean flour fortified diet, date paste (8.0 bee frames/colony) was the next effective one, among the tested pollen replacement diets whereas relatively least (5 bee frames/colony) was noticed in case of grinded groundnut. Highest body weight (12.41 g) of neonate bees was noted in case of soybean enriched diet while lowermost (5.31 g) was noted in control bees. Results of wax cell built up and foraging efficiency were also superior in artificial diets than respective control bees. Hence, artificial diets especially soybean-enriched pollen alternative diet can boost up the physiology of honey bee leading to increased honey yield and profit.     

Regulation of nectar collection in relation to honey storage levels by honey bees, Apis mellifera

Honey bees collect distinct nutrient sources in the form ofnectar (energy) and pollen (nitrogen). We investigated the effectof varying energy stores on nectar and pollen foraging. We foundno significant changes in nectar foraging in response to changesin honey storage levels within colonies. Individual foragersdid not vary activity rates or nectar load sizes in responseto changes in honey stores, and colonies did not increase nectarintake rates when honey stores within the hive were decreased.This result contrasts with pollen foraging behavior, which isextremely sensitive to colony state. Our data show that individualforaging decisions during nectar collection and colony regulationof nectar intake are distincdy different from pollen foraging.The behavior of honey bees illustrates that foraging strategy(and therefore foraging models) can incorporate multiple currencies,including both energy and protein intake.[Behav Ecol 7: 286–291(1996)]     

Comparative floral preferences in nectar and pollen foraging by Scaptotrigona postica (Latreille 1807) in two different biomes in São Paulo (Brazil)

To describe the trophic resources used by Scaptotrigona postica, honey and bee bread samples were taken monthly from May 2015 to December 2016 at two different localities. Fontes do Ipiranga State Park (PEFI), an urban remnant of the Atlantic Forest, and the Mogi Guaçu Biological Reserve (RBMG), in the Cerrado. Two colonies were kept in each site. Samples were analysed with the melissopalynological method in order to calculate the relative frequencies. Principal component analysis was used to compare the similarity between the samples and to examine the influence of quantitative and qualitative data on the ordination of the pollen types. Similarity tests were performed to compare the pollen spectra of the bee bread and honey samples between the study sites and seasons. Hence, 69 and 61 pollen types were identified in 33 honey and 29 bee bread samples. The main families in honey were Asteraceae, Euphorbiaceae and Fabaceae; in bee bread Fabaceae, Myrtaceae and Sapindaceae were the main families for both localities, followed by Asteraceae, Euphorbiaceae and Solanaceae at the RBMG. The results showed that the species maintains its floral preferences regardless of the biome in which it occurs. Also, demonstrates that the bees make use of nectariferous and polliniferous sources available in the preserved areas as well as in its surroundings. There is a risk of pesticides exposure caused by the use of trophic resources of cultivated plants by this bee. This points to the need for further studies.     

Are honey bees' foraging preferences affected by pollen amino acid composition?

Abstract.  1. Although pollen is a vital nutritional resource for honey bees, Apis mellifera , the influence of pollen quality on their foraging behaviour is little understood.
2. In choice-test experiments, bees showed no innate pollen-foraging preferences, but preferred oilseed rape Brassica napus pollen over field bean Vicia faba pollen after previous foraging experience of oilseed rape.
3. The free amino acid content of oilseed rape and field bean pollen was compared using high-performance liquid chromatography. Oilseed rape pollen contained a greater proportion of the most essential amino acids required by honey bees (valine, leucine, and isoleucine) than field bean, suggesting that oilseed rape pollen is of greater nutritional quality for honey bees than is field bean pollen.
4. Honey bee foraging preferences appeared to reflect pollen quality. The hypothesis that pollen amino acid composition affects the foraging behaviour of honey bees is discussed.     

Protein content and amino acids composition of bee-pollens from major floral sources in Al-Ahsa,eastern Saudi Arabia

Protein content and amino acids composition of bee-pollens from major pollen floral sources in Al-Ahsa, Saudi Arabia were determined to investigate the nutritive value of pollen protein relative to requirements of honeybees and adult humans. The major pollen sources were alfalfa, date palm, rape, summer squash, and sunflower. Bee-pollens from alfalfa and date palm showed high content of crude protein and amino acid concentrations. Bee-pollen from sunflower had low content of those components. Eighteen amino acids were found in bee-pollens from the five major floral sources. The highest concentrations of individual amino acids valine, leucine, isoleucine, phenylalanine and proline were obtained from alfalfa bee-pollen; lysine, arginine, cysteine, tryptophan and tyrosine from date palm; methionine, histidine, glycine and alanine from summer squash; threonine, serine and glutamic acid from sunflower; and aspartic acid from rape bee-pollen. The amino acid composition obtained from sunflower bee-pollen showed the lowest concentrations of the essential amino acids: isoleucine, leucine, methionine, phenylalanine and valine. Apart from methionine, arginine and isoleucine, the essential amino acids of bee-pollen from alfalfa, date palm, summer squash and rape exceeded the honeybees’ requirements. Methionine was the limiting amino acid in bee-pollens from the five selected sources. Concentrations of essential amino acids in the tested bee-pollens were variable and significantly correlated to their botanical origin of pollen. Bee-pollens from alfalfa, date palm and summer squash was found to be rich source of protein and amino acids for bees and for humans.     

Nutritional content of fresh, bee-collected and stored pollen of Aloe greatheadii var. davyana (Asphodelaceae)

Aloe greatheadii var. davyana is the most important indigenous South African bee plant. Fresh, bee-collected and stored pollen of this aloe was collected and analysed for its nutritional content, including amino acid and fatty acid composition. Highly significant differences were found between the three types of pollen. Collection and storage by the bees resulted in increased water (13-21% wet weight) and carbohydrate content (35-61% dry weight), with a resultant decrease in crude protein (51-28% dry weight) and lipid content (10-8% dry weight). Essential amino acids were present in equal or higher amounts than the required minimum levels for honeybee development, with the exception of tryptophan. Fatty acids comprised a higher proportion of total lipid in fresh pollen than in bee-collected and stored pollen. This study is the first to compare the changes that occur in pollen of a single species after collection by honeybees.     

Detection of deformed wing virus in the greenhouse for possible horizontal transmission of virus in honey bee colony

The honey bee Apis mellifera L. is a crucial insect in the agricultural industry and natural ecosystem by being a major pollinator. Nevertheless, honey bee population has been recently facing a decline. Among the several factors responsible for this decline, deformed wing virus (DWV) is considered a primary cause that negatively affects honey bee health. DWV is a cosmopolitan honey bee pathogen and causes morphological disadvantages in individual honey bees and colony collapse. Regarding the horizontal transmission of DWV, in addition to Varroa destructor, a well-known major vector of DWV, flowers have recently been implied as a transmission route. Therefore, in this study, we detected DWV from various substances, including flowers, honey bee feces, pupa, larva, nurse bee, surface of nurse bee, pollen collected by forager bee, and forager bee samples in four strawberry greenhouses, which could suggest the potential for the horizontal transmission of DWV in the semi-field condition. We also detected DWV in pollen collected by DWV-negative forager bees, implying that flowers can serve as a potential source of virus infection. These findings suggest that the surrounding environment such as shared floral sources affects the spread of DWV.     

Microalgae as a promising and sustainable nutrition source for managed honey bees

Managed honey bee colony losses are attributed to a number of interacting stressors, but many lines of evidence point to malnutrition as a primary factor. Commercial beekeepers have become increasingly reliant on artificial pollen substitute diets to nourish colonies during periods of forage scarcity and to bolster colony size before pollination services. These artificial diets may be deficient in essential macronutrients (proteins, lipids, prebiotic fibers), micronutrients (vitamins, minerals), and antioxidants. Therefore, improving the efficacy of pollen substitutes can be considered vital to modern beekeeping. Microalgae are prolific sources of plant-based nutrition with many species exhibiting biochemical profiles that are comparable to natural pollen. This emerging feed source has been employed in a variety of organisms, including limited applications in honey bees. Herein, I introduce the nutritional value and functional properties of microalgae, extrapolating to central aspects of honey bee physiology and health. To conclude, I discuss the potential of microalgae-based feeds to sustainably provision managed colonies on an agricultural scale.     

Effects of brood pheromone (SuperBoost) on consumption of protein supplement and growth of honey bee (Hymenoptera: Apidae) colonies during fall in a northern temperate climate

Honey bee, Apis mellifera L. (Hymenoptera: Apidae), nutrition is vital for colony growth and maintenance of a robust immune system. Brood rearing in honey bee colonies is highly dependent on protein availability. Beekeepers in general provide protein supplement to colonies during periods of pollen dearth. Honey bee brood pheromone is a blend of methyl and ethyl fatty acid esters extractable from cuticle of honey bee larvae that communicates the presence of larvae in a colony. Honey bee brood pheromone has been shown to increase protein supplement consumption and growth of honey bee colonies in a subtropical winter climate. Here, we tested the hypothesis that synthetic brood pheromone (SuperBoost) has the potential to increase protein supplement consumption during fall in a temperate climate and thus increase colony growth. The experiments were conducted in two locations in Oregon during September and October 2009. In both the experiments, colonies receiving brood pheromone treatment consumed significantly higher protein supplement and had greater brood area and adult bees than controls. Results from this study suggest that synthetic brood pheromone may be used to stimulate honey bee colony growth by stimulating protein supplement consumption during fall in a northern temperate climate, when majority of the beekeepers feed protein supplement to their colonies.     

The immunological dependence of plant-feeding animals on their host’s medical properties may explain part of honey bee colony losses

The honey bee (Apis mellifera) is an important pollinator of agricultural and horticultural crops, but also of wild flowers. The species has been facing declines in many areas of the world, the causes being identified as multifactorial. Recently, it has been theorised that some plant-dwelling animals may develop a dependence on the medicinal properties of their hots plant’s secondary metabolites. Here, the question of honey bee self-medication using organic materials, namely propolis, nectar, honey, honeydew, pollen, wood, and algae for self-medication is addressed. Self-medication in honey bees is a largely unexplored area and thus a comprehensive overview of the field is provided. Prior studies suggest that recent honey bee colony declines are driven by decreased forage plant availability. The problem is expanded and it is suggested, that if honey bees developed a dependence on medical properties of some disappearing plants or materials, this could explain a part of the colony losses observed around the world. To date, convincing evidence points towards self-medication with honey and propolis. Bees also contact plant secondary metabolites, fatty acids, essential oils, and microorganisms that are active against the causative agents of American foulbrood, European foulbrood, nosemosis, chalkbrood, stonebrood, and varroasis. In the future, selected taxa of plants with medicinal properties may be planted to boost honey bee health without chemotherapy. Future directions of research are discussed.     

Characterization of the active microbiotas associated with honey bees reveals healthier and broader communities when colonies are genetically diverse

Recent losses of honey bee colonies have led to increased interest in the microbial communities that are associated with these important pollinators. A critical function that bacteria perform for their honey bee hosts, but one that is poorly understood, is the transformation of worker-collected pollen into bee bread, a nutritious food product that can be stored for long periods in colonies. We used 16S rRNA pyrosequencing to comprehensively characterize in genetically diverse and genetically uniform colonies the active bacterial communities that are found on honey bees, in their digestive tracts, and in bee bread. This method provided insights that have not been revealed by past studies into the content and benefits of honey bee-associated microbial communities. Colony microbiotas differed substantially between sampling environments and were dominated by several anaerobic bacterial genera never before associated with honey bees, but renowned for their use by humans to ferment food. Colonies with genetically diverse populations of workers, a result of the highly promiscuous mating behavior of queens, benefited from greater microbial diversity, reduced pathogen loads, and increased abundance of putatively helpful bacteria, particularly species from the potentially probiotic genus Bifidobacterium. Across all colonies, Bifidobacterium activity was negatively correlated with the activity of genera that include pathogenic microbes; this relationship suggests a possible target for understanding whether microbes provide protective benefits to honey bees. Within-colony diversity shapes microbiotas associated with honey bees in ways that may have important repercussions for colony function and health. Our findings illuminate the importance of honey bee-bacteria symbioses and examine their intersection with nutrition, pathogen load, and genetic diversity, factors that are considered key to understanding honey bee decline.     

Unique Honey Bee (Apis mellifera) Hive Component-Based Communities as Detected by a Hybrid of Phospholipid Fatty-Acid and Fatty-Acid Methyl Ester Analyses

Microbial communities (microbiomes) are associated with almost all metazoans, including the honey bee Apis mellifera. Honey bees are social insects, maintaining complex hive systems composed of a variety of integral components including bees, comb, propolis, honey, and stored pollen. Given that the different components within hives can be physically separated and are nutritionally variable, we hypothesize that unique microbial communities may occur within the different microenvironments of honey bee colonies. To explore this hypothesis and to provide further insights into the microbiome of honey bees, we use a hybrid of fatty acid methyl ester (FAME) and phospholipid-derived fatty acid (PLFA) analysis to produce broad, lipid-based microbial community profiles of stored pollen, adults, pupae, honey, empty comb, and propolis for 11 honey bee hives. Averaging component lipid profiles by hive, we show that, in decreasing order, lipid markers representing fungi, Gram-negative bacteria, and Gram-positive bacteria have the highest relative abundances within honey bee colonies. Our lipid profiles reveal the presence of viable microbial communities in each of the six hive components sampled, with overall microbial community richness varying from lowest to highest in honey, comb, pupae, pollen, adults and propolis, respectively. Finally, microbial community lipid profiles were more similar when compared by component than by hive, location, or sampling year. Specifically, we found that individual hive components typically exhibited several dominant lipids and that these dominant lipids differ between components. Principal component and two-way clustering analyses both support significant grouping of lipids by hive component. Our findings indicate that in addition to the microbial communities present in individual workers, honey bee hives have resident microbial communities associated with different colony components.     

Free amino acids in the haemolymph of honey bee queens (Apis mellifera L.)

In queen honey bees the free amino acid content in the haemolymph clearly depends on the physiological function and social environment of the individual. While in drones and workers the content of free amino acids increases after emergence until it reaches a peak in 5-day-old animals and decreases afterwards, the amino acid content in queens reaches its highest level (>60 nmol/ microl haemolymph) with the onset of egg laying (10 d of age). This level is about 2.5 times more than the highest level found in workers. Queens maintain this high level also when they are older (>30 d) and continue to lay eggs in average colonies. As in drones and workers, in queens the predominant amino acid is proline, which accounts for more than 50% of the total content of free amino acids in egg-laying individuals. When 10-day-old queens are prevented from mating and do not lay eggs, their amino acid content is significantly lower compared to laying queens of the same age. Also the social environment influences the contents of free amino acids in queens. When virgin queens were kept for 6 days with 20 worker bees and sufficient honey and pollen in an incubator, they had significantly lower concentrations of amino acids than virgin queens living for the same period with about 8000 workers in a colony. Most probably, the high amino acid concentration in the haemolymph is the basis for the high protein synthesis activity of laying queens.     

Brood Pheromone Modulation of Pollen Forager Turnaround Time in the Honey Bee (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.)

Foraging for pollen is an important behavior of the honey bee because pollen is their sole source of protein. Through nurse bees, larvae are the principal consumers of pollen. Fatty acid esters extractable from the surface of larvae, called brood pheromone, release multiple colony-level and individual foraging behaviors increasing pollen intake. In this study pollen forager turnaround time was measured in observation hives supplemented with brood pheromone versus a blank control treatment. Treatment with brood pheromone significantly decreased pollen forager turnaround time in the hive between foraging bouts by approximately 72%. Concurrently, brood pheromone increased the ratio of pollen to non-pollen foragers entering colonies. Brood pheromone has been shown to release most of the mechanisms known to increase pollen intake by colonies acting as an important regulator of colony foraging decisions and growth.     

Effect of growth temperature and media composition on the fatty acid composition of Bacillus stearothermophilus AN 002

The influence of growth temperature, media composition and cell age on the chemical composition of Bacillus stearothermophilus strain AN 002 has been determined. The total cellular protein decreased and the free amino acid content increased with growth temperature, in both exponential and stationary growth phase. The protein and free amino acid contents of cells were higher in the stationary phase than in the exponential phase, irrespective of growth temperature and media composition. The RNA content was only reduced in cells grown at 55° C. No significant variations were observed in the DNA and carbohydrate contents with respect to growth temperature and cell age. The total lipid and fatty acid compositions on the other hand varied as a function of growth temperature, cell age and media composition. Differences in the relative concentrations of even, odd and branched chain fatty acids were noticed. Novariation was observed in the antiiso and unsaturated fatty acids with respect to growth temperature. The unique variations in the fatty acid composition and total lipids at the growth temperature of 50° C and their variations in the stationary growth phase seem to be characteristic for B. stearothermophilus AN 002.     

Free fatty acids digested from pollen and triolein in the honeybee (Apis mellifera carnica Pollmann) midgut

Honey bees satisfy their lipid requirement by consuming pollen. The free fatty acid content of the midgut was used to quantify fat digestion. Midguts extracted from younger workers of known ages and from foragers were divided into three components: endoperitrophic region (peritrophic membrane with gut contents), extraperitrophic region and intestinal wall. Both the total amount of pollen and the amount of free fatty acids in the endoperitrophic region and in the intestinal wall depend on the bee's age. The amounts increase within the 1st 3 days of a honey bee's life, reach maxima around the age of 8 days and then decrease continuously to the lowest values, measured in forager bees. Forced feeding with triacylglycerol results in significantly higher levels of free fatty acids, especially in the endoperitrophic region, in 8-day-old bees and foragers. This indicates that lipolytic activity depends on age and that the free fatty acid content in 8-day-old bees is primarily limited by the amount and availability of lipids ingested. The results show further that fat digestion depends on the functional status of honey bees, as is the case for pollen consumption, speed of transport of pollen bolus through the alimentary canal and protein digestion.     

花粉破壁法对花粉蜂蜜酒中氨基酸含量的影响

以蜂蜜为主料,加入花粉,经过调配、发酵、过滤、陈酿后获得氨基酸含量丰富的酒精饮料。花粉破壁分别采用超声破碎法、酶法和温差破壁法这几种不同方式处理,并添加于蜂蜜发酵液中,经酒精发酵,制得富含活性成分的花粉蜂蜜酒。最后利用毛细管电泳法来测定成品酒中的氨基酸,通过分析优化出最佳的花粉破壁方法。研究结果表明花粉经过温差破壁法处理后加入发酵液中,其成品的氨基酸含量最高。该产品不仅营养价值高,风味独特,而且还具有良好的保健作用。